Rageborn Beastmorph Vivesectionist Alchemist 5th Level1: Feat: Extra Feature
2: Discovery: Feral Mutagen
3: Arcane Strike
4: Discovery: Spontaneous Healing
5: Power Attack/Multiattack
Right you have 3d6 Sneak attack die, and attack with 2 Hooves at 1d4 (Secondary attacks), 1 Gore at 1d6, 2 claws at 1d6, and 1 bite for 1d8.
Additionally all these attacks have a +2 damage thanks to Arcane strike
So you deal a minimum of 18 damage if everything hits and rolls a 1 without sneak attack die. That is your minimum damage once you have hulked out.
Sorry to nitpick, my understanding was alchemists do not qualify for Arcane Strike as they don't cast arcane spells--when has this changed?
A less optimized but IMO fun and versatile combination is bard/dragon disciple; see Oterisk's guide here on the forums for details.