In the Marvel comics Carnage, Deadpool, Sabretooth, Wolverine and their clones X-23 and Danken are immortal, and all are indestructible apart from Wolverine and his brother which can be killed by decapitation, but as long as their skeleton is intact they will regenerate everything as seen in the nitro explosion.
At what levels can any of this be realistic? And how?
In the real world :
Can any of them develop (evolve) naturally as a species?
How many calories would they need daily to survive this way?
Can Wolverine, X-23 and Danken survive with metallic bones?
How can all of them regenerate full limbs within days,and instantly in fight?
Can Deadpool regenerate his own head and brain while remaining the same person?
Can a symbiote like creature be compatible with any animal?
Where do they get infinite matter to regenerate their whole bodies?
Can a symbiote be liquid-like ?