Greenfist is a dinosaur-like boss that appears in Wario World. He is the boss of Greenhorn Forest, the first level. His arena consists of a single, small green platform. To beat him Wario must punch him enough times to stun him, then destroy one of his health skulls with a Piledriver, Wild Swing-Ding, or Power Throw. He can also lose a health skull just by falling off the battlefield.
Greenfist has just two attacks. In the first, he attacks Wario with a powerful slam from his fists that flattens Wario on contact. Wario must be standing right in front of Greenfist for the attack to connect. Greenfist uses his second attack after receiving some punches from Wario. He charges up and runs after Wario, flailing his arms wildly. This attack gets faster and thus more difficult to dodge as Greenfist loses health. It is also possible to give Greenfist two damage by using a Power Throw and throwing him off the cliff.
After three powerful moves, Greenfist is defeated, coughs up a large amount of coins and Wario is allowed into Greenhorn Ruins. Greenfist is the first of the three bosses in Excitement Central. SandWorm is the second, and Dinomighty is the third.