The Terrarian is an endgame-tier Yo-Yo that can be dropped by the Moon Lord, the most powerful yoyo in the game. With a base damage of 190, this is easily one of the highest-damage weapons in the game. It rapidly shoots out small homing green projectiles that do the same damage as the yo-yo itself with short range. While it does not have highest base damage (Meowmere is higher at 200 base damage with the blade only), it attacks much faster therefore has better DPS. The Terrarian is not buffed by the Yoyo Glove, however, the Yoyo Bag still affects it. Just picking up the yoyo earns the achievement "Sick throw". It can can remain in the air indefinitely, one of the only few yoyos that have such capability.
One Drop Yoyos have created a yoyo based on the Terrarian.