The Thorn Bug is a hostile arthropod native to and affiliated with the Poison Forest biome. It spawns in the Poison Forest biome near Thorn trees.

The Thorn Bug looks like a green rectangle with red eyes and a large red thorn on it's back. The thorn bug has a large jumping ability, able to jump 2 blocks high. The thorn bug is also able to climb wood like a spider climbs any substance it needs to.

The Thorn Bug's primary purpose is to kill off enemy mobs, as such, it will attack the player or any non-poison forest mobs it encounters. It does 5 hearts of damage and has 8 hearts of health.

As a poison Forest Mob, the Thorn Bug will be attacked by non-poison forest hostile mobs, boss mobs, wolfs, and utility mobs.