User blog comment:Spdr man/symbiotes/@comment-4652104-20120914211035

Frankly, I don't know many of these characters, apart from Venom (although I do know one you missed, appeared in the War of Kings and possessed Raza Longknife for a time),y but I would suggest a few things:

Firstly, this may be purely due to different drawing styles. Different artists may have varying visions of the symbiotes. Also, they may simply draw stuff differently.

Secondly, the looks or maybe even some of the powers of the symbiote may reflect the personality of the host. And it seems that some of this personality is left, especially from the first host or a particularly strong one. This would explain why Venom has more Spider-Man like features than Carnage or other symbiotes. Eddy Brock was fully "integrated" with his symbiote. This gave him a consistent look, unlike spider-man, but not completely monstrous. Gargan took on the spiderman-like form for the Dark Avengers, possibly thanks to some manipulation by Osborn. Flash Thompson's look may express his military outlook. In both cases Venom becomes truly monstrous when they let loose.

Lastly, perhaps not all symbiotes are identical or have the same powers. Maybe every symbiote is different, or maybe Venom is a "mutant". Remember the symbiotes Dr Doom accidentally dropped on Manhattan in Mighty Avengers? Totally mindless, but in complete control of the host. Do you think they were bio-engineered by Doom to have these features, or is this actually your baseline symbiote and Venom is somehow special?