Nessus is a large centaur, who is known as the "River Guardian". He is a minor villain in the film Hercules.
Megara was sent by Hades to recruit Nessus for his army. In exchange for his service, Nessus wanted Meg to be his lover. Meg's refusal only made Nessus more persistant. Thankfully, Hercules showed up, and told Nessus to unhand her. However, his command didn't faze Nessus. As soon as Hercules pulled out his sword, Nessus uppercut him, and sent him flying away. Looking for his missing sword, Hercules instead found a fish, that screamed when it saw Nessus and jumped away, much to Nessus's amusement. Nessus then punched Hercules into a rock. Philoctetes then told Herc to use his head. Not quite understanding what he meant, Herc literally used his head, by headbutting Nessus, sending him flying.
Nessus wasn't done yet, and charged towards Hercules, who leaped into battle and clearly outmatched Nessus, beating him down. Hercules even rode Nessus, before he slammed him into a tree. Nessus then turned to Hercules, before being punched into the air. Nessus eventually fell back into the lake, and was hit on the head with his four horseshoes. Three of them formed a large lump, while the last one caught around it. Pegasus then approached him, and blew him over with a simple breath, before he stomped on his head.