Family Events

A Family Event is a rare event which has a 2% chance to occur for the entire duration of a typical stage. A Family Event will restrict the kinds of Monsters that can spawn to a specific, limited selection; including monsters spawned by and during the Teleporter Event. The specific pool of monsters is signaled by a line of pink text at the beginning of the stage.

Family Events commonly result in monsters spawning in Environments they are otherwise unable to spawn in, such as the Grovetender spawning in Environments other than Scorched Acres.

Trivia

 * The Parent and Mini Mushrum Family Events are the only ones to feature a single Monster.
 * The existence of these Family Events are possibly tied towards future planned or previously scrapped Monsters, with the unused/unfinished Grandparent Boss giving precedent to this theory. Additionally, the Mini Mushrum was simply named "Mushrum" in Risk of Rain 1, which suggests that a larger monster related to it was a planned addition.