Mushroom Boi!

The  is a power skill exclusive to the Bad Seed DLC. It spawns a friendly Jerkshroom which attacks nearby enemies.

The Sacrifice
The Mushroom Boi is part of a sacrificial ritual that grants the player the Sacrificial Tick Outfit. To initiate this ritual, the player must go to the Morass of the Banished. In it, the player must reach the end of the biome, where a masked individual known as the Swamp Priest resides. The Swamp Priest stands next to an altar that depicts Mama Tick, he nags the player to offer a sacrifice, namely the Mushroom Boi. If the player complies, the Mushroom Boi is completely removed from the player's inventory and the subsequent fight that should take place in the Nest will not occur. This ritual can be repeated in subsequent visits with the same result, but the outfit can only be obtained the first time unless the player did not hand it over to the Collector.

If the player has a ranged weapon in their inventory and manages to attack Mama Tick in the brief moments she raises her eye above the water, the fight begins as usual and the outfit blueprint will not be dropped.

Trivia

 * The Mushroom Boi! is the second pet skill to be added to the game, with the first being the.
 * It is so far the only item in the entire game that contains non-alphabetical characters in its name.
 * Mushroom Boi! is the only item required to obtain a blueprint of an outfit.
 * There is a visual glitch that occurs when you teleport anywhere and have activated Mushroom Boi! that makes him appear to be crouching, similar to the Jerkshroom Hide defensive ability.