ok, ideas for Mutant legacy, well we are lacking a lot invertebrates and birds, it'd be interesting to see a Starlings mutant (They are highly social birds that form large flocks, exhibiting a distinctive swarming behavior called murmuration. Additionally, starlings are fantastic mimics, capable of reproducing a wide variety of sounds, including those of other birds and even machines, some reports claim they make calls to are almost human) a mutant Starlings would probably fly in flocks using a their own sophisticated language (like the brain capacity of a dolphin) in flocks they'd mimic the voices of prey animals or predators to startle prey into a corner.
