Slugcats are both the primary protagonists and the main playable characters of Rain World. They are small creatures that can come in various colors, and with black or white eyes, thin arms, broad legs with small feet, broad-ended ears, and a thick tail that tapers at its end. The player must keep the Slugcat they play alive as they explore the world, confront strange Creatures, and take part in completing challenging Achievements. The Slugcats have a variety of movement abilities, which can be seen in detail on the Controls page.
Upon first starting the game, the player has the option of playing as two different Slugcats: the Monk and the Survivor. After finishing the game as either the Monk or the Survivor, the player unlocks the ability to play as the Hunter, the Artificer, and the Gourmand (The Gourmand, Artificer, and following Slugcats are all only available if the Rain World Downpour DLC is installed, and the More Slugcats mod is enabled). After finishing the game as either the Gourmand, the Artificer, or the Hunter, the player unlocks the ability to play as either the Rivulet or the Spearmaster . Once both the stories of the Rivulet and the Spearmaster are finished, the Saint will be unlocked.