Our group goat mascot / animal companion could use some additional natural attack forms for additional damage types right now (and definitely by 9th level when it gets Multiattack). He only has a primary Gore attack currently, but the GM is letting us assign the three feats he would have got for levels 1-5.
Inspired / based on this question
I'd rather stay away from Evolved Companion if possible because the character with the companion has already spent those feat slots and won't get another until 7th level.