Chasmward

Found in

Loot table	Quantity	Drop rate
Earth Key	1	0.0029% (1 in 34,500)

Chance per kill, from the game's loot data: one loot pass on an unscaled map. Party-scaled instances roll the same tables again, so these are floors, never ceilings. A rate marked "at least" is one whose roll count depends on data this wiki does not carry.