Well in essence the 'skin wrap' from the category isn't the same thing. 1: It can't be 'removed' shy of surgery. 2: They can not only be concealed by clothes, they can become what ever clothing that they wish to. They can even be concealed in the blood stream of their hosts in some cases. As to the 'slimy' or what ever part, that's more for flavor. I always thought the symbiotes were more like animated spandex or 'skin' depending. Some skin can be slimy and many of them are often shown gnarly, but it seems more for flavor than a default state. Wasn't slimy at all on Spidy and on some others.
I don't know much about Blue Beetle, but if memory serves is scarab wasn't an alien symbiote, but some flavor of enhanced object? The one's from HU2 are like the crap out of Atlantis. Giant crabs that dig their claws into your chest, or bugs or slugs type thing.
Regarding the powers, that's where it gets tricky. Like many comic heroes/villains, to even come close you'd need to go mega hero.
Greetings and Salutations. Addressing the skin wrap ...
1: Fair enough. I know (again, haven't read the comics for years, and only read some even back then) the Symbiotes were pretty hard to remove. I know Spiderman needed to see the Fantastic Four to have his removed (I believe that's how he did it), and getting rid of the Carnage symbiote is all but impossible. The Venom symbiote has willingly left Brock, though it didn't like it at all (from what I've read). So yeah, a little different, but I don't see it as a huge difference either (because getting rid of the symbiotes was always problematic).
2: This is true. But I actually considered that more of another super power akin to Shapechanger, but only for the symbiote.
3: Yeah, that's a problem with almost all comic heroes/villains. I won't argue that one.
As for Blue Beetle ... yes, it's an object created by the Reach akin to the Green Lantern power ring (to my understanding), though with a very different purpose. However, it has an intelligence (unlike the ring) and it's actually dug into the spine of Jaime Reyes. So while technically an object, I think the concept of a Symbiote (even if not 100% accurate) seems to fit the build better. Mind you, that's the current Blue Beetle (not the older ones such as Ted Kord who was closer to Batman).
As for a solution to the Symbiotes, I still think Symbiont works best (a Mega-Hero version of it) for the starting build. I had looked at Gestalt (because it's really two beings), but that just didn't seem like it would fit well at all.
Building an Alien that's similar might work, but I don't see any creation rules in the Alien section that would reflect a sybmiote well (maybe in AU?).
Other options might include something like Mystically Bestowed Abilities (which mentions things like a sick or incapacitated individual gaining full power as a result).
However, in the end, I don't think any single category would fit the Symbiote with 100% accuracy. There are elements from various places, but not exact replicas. Either you'd have to pick the one that best fits the concept (and/or modify from there), or build something original (well, not exactly original since it's a conversion, but start fresh). Personally, I think the Symbiont skin cover works, make it a Mega-Hero, and from there would just try to pick the powers that I think best represent the symbiotes (and not worry about giving them ALL of the powers, just enough to work).
P.S. Mega-Heroes automatically have Supernatural Strength and Enhanced Healing. And while the symbiotes may be fast, I don't recall them ever being able to run 220+ miles an hour. Being fast or agile does not automatically equal Extraordinary P.P. or Spd. Something lesser like Physical Perfection (PU1) might help represent that increase (PU1 also has the Web Shooter equivalent).
You bring up a couple of good points. So I'll see how I can build off of those. Starting with the understanding that HU isn't truely built to represent the BIGGIES of Comics. Thor/Superman/Hulk/ and yes. Spiderman, which would mean Also Venom as he's as strong or stronger than Spidy, but we'll see how close we can get.
1: Mega Hero.
A: Supernatural PS (Reflecting the Symbiote's huge strength. They're regularly seen throwing cars and being at least if not stronger than Spiderman
B: Increase SDC by 50% (This is a good start, as many of the Symbiote's have taken full blasts from Machine guns at point blank with out too much trouble. This would likely be represented by a high AR, but the added SDC Helps
C: Enhanced Healing. (Another good start. In the comics I'd rate their healing almost on par with Wolvies but this helps get you where we're aiming
D: Increased range 50%: Again this helps get us towards where the Symbiotes are in the comics.)
2: Special Mega Powers: Now, the book says one, but allows for two if your GM is down for it. Lets assume for purpose of trying to replicate the power level of such a biggie, that we're allowed two
E: Tremendous SDC: Add 1D4X100+160. (This adds in with "B" above to show how tough the Symbiotes are, with out having to spend one of our 'super abilities' on it)
F: Tremendous PS: Add 20 to your Supernatural PS and get death blow. (Again this helps to show how powerful these things are, even at lvl 1. Mania, for example was just a spat out, re-absorbed, copy of the original, and with in seconds of touching her host, was able to rip through walls and such. )
(Technically, "Doesn't need air to breathe" and "Impervious to disease" would also fit, but those are situational and more 'minor' than E and F above which are 'Needed" to try and replicate the comic)
3: Achilles Heel
G: Fire. (The Symbiotes were often shown to have trouble with fire.
H: Powerful Sonic attacks (The primary weakness of the Symbiotes)
4: Powers: 2 Major
I: Chameleon: While this might not seem intuitive at first and many would go "animal Abilities: Arachnid" When you look at the break down this one works better. You get Adhesion, and hold breath, which helps to mimic not needing air (Which we had to skip above) It also gives the Cameleon power, which many of the symbiotes have shown to have, blending in with shadows and stuff. The power gives you a natural prowl skill at a decent level, additions to disguise and climbing. The Animal Abilities Arachnid, gives Adhesion, and a poisonous bite, which Venom and a few others have shown once or twice. I just don't see the total package being as good over all as Chameleon does. And the Chameleon package mimics the wall crawling mechanically.
J: Monstrous Form: This fits on many levels.
J1: Transformation. The Symbiotes all have shown the physical transformation of the host when the Symbiote does it's thing. While some don't grow huge, most seem to bulk up and change the appearance
J2: Monster Body Masks the true appearance and gives claws:2D6, but remember we've already got Supernatural PS and Tremendous PS to add onto that, so it fits. Also adds to Climbing
J3: Monster AR and SDC: AR is 1D6+8, and 3D6X10+40 SDC is added. This again stacks with the previous bumps to represent the toughness of the creatures
J4: Alignment Change: While often over looked (As most of us just play our char's and don't mess around with Palladium's Alignment things) It actually fits. Most of the Symbiotes were kinda wacked and even on 'good guys' urged them to do things they wouldn't normally. So the Shove down a 'step' on the Alignment chart actually really fits.
J5: Special Abilities in monstrous form (Symbiote 'on/active) The book says you get 1D4+2. Each char could roll, but in the attempt to mimic the creatures I'm going to assume 4+2 for a total of 6
J5:1-2: Bio Regeneration: Superior (Counts as 2, and represents the healing factor that they have.)
J5:3: Combat Reflexes: Offensive: Adds alot of bonus and damage to Hand to hand, which helps with the claws and such. Also adds an attack per round
J5:4: Increase Speed and Leg Muscle Strength: Adds to speed, and leaping. Which the symbiotes have. (While they can't run at 220mph, any write up for them you find always lists Superhuman strength, endurance, agility and speed. So this helps there.
J5:5: Tough Skin: Adds another 100 or so to (SDC which again helps the over all concept.) J5:6: Combat Fangs: 3d6+1d6 from the offensive combat reflexes+the supernatural strength. (The symbiotes on everyone other than spiderman have shown wicked maws. Some extremely so. So this one represents that.As a GM I'd also allow this to represent the sort of bladed body weapons that they routinely make, but that's a GM call. Not straight from the book. Add this in with the next)
Powers: 3 Minor
K: Extraordinary PP (Reflective of the agility that's bestowed. In truth, for these as well as Spiderman (Gambit, etc) Should have a higher level, Super human PP, and even a major, Supernatural PP, but as we don't have those 'by the book' We go for Extraordinary PP)
L: Lightning Reflexes. (Again to augment the physical prowess and uncanny agility and reaction times of the symbiote)
M: Tentacles of Hair: (Actually the 'suit' extending parts of itself, not 'hair', though there was one that used their hair for this.) This actually fits better than 'swing line', as listed in the books. The Marvel Wiki lists The Symbiote's webbing can shoot 70 feet. The Tentacles of hair (suit) have a range of 40 feet but mega hero adds 50%, so this gets us to 60 feet. Which is more or less 70. Close enough to fudge it and call it 70 It can be shown as webbing or in later versions the symbiotes shoot out ropy tentacle strands of the same substance that makes up the suit itself. They're also animated and have half the strength of the main character. When you look at the stack of Supernatural PS we have on the main character, this is great. You can also use them in combat.2D4+1d6(From monstrous form combat) and add in the Supernatural PS, it gives them some heft.) If you add on the 'Combat fangs' in the form of blades or sometimes even mouths on the end of these, they represent the symbiotes even more. Even the 'webbing' formed by the suits is made -from the suits- this is very clearly stated in the lore, as Spidy used it as a weakness once, making Venom expend huge amounts of webbing, trying to catch him and it weakened the suit)
So, with that, so far we have a mega hero with 2 majors and 3 minors. Pulling up the Marvel Wiki and checking the powers it has listed for the Symbiotes.
1: Superhuman Strength: Lists as "Slightly greater than spider man" all the way up to being able to trade blows with the Juggernaut. (I think we have this covered with the Supernatural PS and Tremendous PS)
2: Superhuman Durability: Said to be able to withstand high caliber bullets etc ( I think this is covered with our tremendous SDC and the other additions to SDC)
3: Superhuman Stamina: In HU this is often combined in with Durability and what not, the increased PE that was picked up along the way helps here
4: Accelerated Healing Factor: (We picked this up in the Monstrous form sub ability)
5: Wall Crawling: (Picked this up in the Chameleon ability)
6: Webbing generation: We picked this up in the minor power.
7: Camouflage Ability: (This is covered in Chameleon power.)
8: Constituent-Matter Manipulation: This is what they call the symbiotes ability to form blades, axes, spikes etc from the suit. We have it covered under the tentacles+the combat 'fangs'. The 'fangs' in this instance being the protrusions formed by the suit.
So we've got those covered. What we were not fully able to replicate is thus
1: Genetic Memory: To my knowledge there's not a related HU Power
2: Offspring Detection: Eh... While very useful, it'd have to be a custom power. Might just get it as a freebie.
3: Constituent-Matter Generation: Venom can also use the same substance comprising the symbiote in the form of constituent black matter or goo, and uses it in this method for lethal force against criminals. Venom can send a part of the symbiote and direct its movements into a victim's body, smothering them from the inside. We 'could' do this with the anatomical independance minor ability, but we ran out of power slots, 'by the book'
4: Esp: Spider sense: A modified version of Spidermans Spidersense. The wiki says theirs is even better than spidys. This could be represented by Danger sense or the like, but we ran out of power slots.
5: Poisonous fangs: Just what it says: There are a couple of ways to mimic this in the rules, but Venom only used it once, and to spend a power slot on it seemed a waste.
6: Stretching and Deforming: This is listed as a power but it's unclear how much is 'power' and how much of it is 'Different artists drawing the symbiotes differently" as in styalistic. Some seem to have elongated arms and such when they're doing their thing, but in the same panel a normal cop might have an arm that looks about 6 feet long or so. So there's something to be said that this is artistic license, vs actual power.
So with this power work up we can pretty well mimic the powers of the Suits. Sure there's some we're missing, but what we're 'keeping' is the big part. ANd what we've had to leave off, while containing some useful things, aren't MAJOR to the thing we're trying to create.
So now, where do we stick it? It could fit under the Alien Category with some slight modification. Or we could keep it in the Symbiote category, and just use the above as the symbiote itself. Or a few other categories actually. Two Majors and 3 minors is a good hefty amount of powers, but multiple power categories have that as one of their options. So... if you use the Mega Hero category and the 2 Major 3 minor.. it's very strong, but not "OP" in HU.