Botwoon

Botwoon is an aquatic snake that resides in Maridia. When Samus encounters him, he will swim around the room and enter and exit four holes in the room. He will sometimes poke his head out of a hole and spit objects at Samus that will damage her. To defeat him, Samus must wait for his head to appear and fire Missiles or Super Missiles at it. As he takes more damage, his color will change and he will speed up. Once he has been defeated, Samus can continue exploring Maridia.