- "Ssso...you are the outsssider, come to wake the Wind Fisssh... KEEE-HEE-HEEEH! I shall eat you!"
- — Slime Eel
The Slime Eel begins the fight by breaking four holes in the walls, then swings its tail around from a hole in the center, which Link must dodge. When its head pops out of one of holes, Link must use the Hookshot to drag it to him and strike its heart. Each time he strikes it, the process speeds up, requiring more skill from Link's end.
Sometimes, when Link uses the Hookshot on Slime Eel, a fake eel will come out instead. This fake eel will start attacking, running around in a manner similar to Moldorm, before self-destructing. Once Link has attacked its heart enough times, Slime Eel will be defeated and Link can retrieve the Wind Marimba. This is the first boss to give a "final warning message" when defeated, accompanied by grim music. It simply warns that Link does not know what kind of island Koholint Island is.
By staying in one of the corners (the bottom ones are usually easier for orientation), the tail can be avoided and Link can use the Hookshot on it when Slime Eel comes out of the corresponding top hole, then slash quickly with the seashell sword to defeat it after around three pulls.