The Katalund Key open Katalund dungeon.
Katalund is a high level “planet” dungeon introduced for Month of the Mad God 2019. Like the rest of its kind, it is a timed gauntlet dungeon where players race against the clock to dispatch waves of enemies for loot.
This dungeon is a source of numerous potions, Katalund Tokens, and various pieces of alien gear.
Wormholes to Katalund spawn randomly when the Alien UFO event boss is slain.