PC/Mobile
PC
Dimensions or Services it affects
PvP
Your in-game account name
da Creeper
How often it happens
People can abuse this mechanic to spawn prismatic lacewings, which in return spawns the boss. It can also kill people.
Any screenshots or videos showing the bug
Note that I saw someone named Yo spawning it earlier, but I forgot to record. I tested the bug in a duel arena to not interfere with anything.