Re: Monster Vol 1

Re: Monster Vol 1 by Kanekiru Kogitsune. An Action manga rated Teen, published in English by Seven Seas in 2016.

Tomokui Kanata is murdered and reborn as a goblin in a fantasy world, with his memories intact and a strange new power: he gains abilities by eating. Starting as the weakest monster, he devours his way up the food chain and builds a powerful clan.