Yet more mutations

So far:
Tentacle upgrade, after Logrin's request
Digestive upgrades for post-Thresh Rats, Chimeras, et al
Albinism as a starting trait (anything that's rainproof keeps the sun off too)
Plants get Vines, which actually become useful post-Threshold
Saber Teeth, Feline post-thresh that does damage and gets in the way
Hyper-Metabolism.  Eat to heal!