Gelatin World Tour

Every slime variety killed - and the list is longer than you'd think: the colour family, biome slimes (sand, jungle, ice, dungeon, lava, shimmer), the rare Pinky (Pretty in Pink) and Rainbow Slime (hardmode Hallow during rain), King Slime and Queen Slime, the Corrupt/Crimson variants, and the seasonal party/event ones... the tracked set is broad, so expect the last few to be the rare spawns. The Bestiary's slime pages double as your checklist - anything without a kill count still needs squashing. Rainbow Slime is the usual final holdout: Hallowed surface, rain, patience.