A lots of new active abilities are now in the game. It could be nice if they could be obtained by mutants, even if it's a minimal probability.
I think about all nymphs's abilities, scarab, stone skin....
The scarab active ability is devour, which you can get already from mutants. By stone skin, I assume you mean the Earth Nymph's Petrify/Basilisk Blood ability?
You, actually do have a small chance to get one of those abilities, but it requires either extreme luck or use of other skills. Because invulnerability and mutation take up the same slot in the info box a creature can only be one or the other. So if you get a mutant with the hatch ability and you make it immortal (through Quint, Anubis, or Aether Nymph) the hatch will no longer be a 'mutation' but will be just like a fate egg hatching and you could get a nymph with nymph ability or scorpion with venom.
The extreme luck way is to get a Graboid with Hatch. Because it is already burrowed, it is invulnerable--and what ever it hatches into will not be a mutation. The resulting creature will also be burrowed!