"Feed me Strabby. Poke Snaktivator in foot. Foot turns into Strabby."
The Snaktivator is an invention created by Floofty Fizzlebean.
Floofty gives the Snaktivator to the player upon first meeting them in Simmering Springs. Once in the player's possession, they can choose which part of a Grumpus's body will change after eating a Bugsnak.
Later, upon meeting Floofty for the second time in Boiling Bay, they will upgrade the Snaktivator, allowing the player to fully customize a Grumpus with any Bugsnax they have previously eaten.