Cabbage Facepunch Bonanza is an emote released during the 2014 Spring Event, Cabbage Facepunch Bonanza. By surviving 40 (non-consecutive) rounds of the event as a human, you will unlock this emote. This does not need to be purchased with renown.
The emote is different for each player, based on the player's faction in the event. Followers of Brassica Prime kick a monkey, followers of Marimbo kick a cabbage, and followers of the Godless kick either a cabbage or a monkey the first time followed by the other one (either the cabbage or the monkey, depends on first one) the next time they do the emote.