Extinctions are strangely-shaped yellow monsters found in the Underworld. They fly around and shoot burning asteroids which can ignite the player to death. They are sought after as they drop Extinction Rods which are an extremely effective fuel source and are used to make various alchemy items. They are also necessary to kill to get to Wyve. In addition, Extinctions drop a lot of XP. They are ambiguously electronic, making clanging sounds when harmed, constantly emitting smoke and heavily breath like Darth Vader, but it is improbable that they are truly mechanical. Their surprisingly most effective weakness is everything related to water. While you cannot bring any into the Underworld, you can chuck snowballs to kill them. RRRRRRR, RRRRRR....