Muddee is a salamander-like boss appearing in The Stagnant Swamp in Wario Land 3.
When Wario uses the turtle to get passed the currents, Muddee appears and scares the turtle away, and before the turtle runs away, Wario has to climb the grillage or he'll fall into the currents. Muddee's main attack is to jump from the water to hit Wario with his spiked tail.
To defeat him, Wario has to use his ground pound on his body, but never touch his spiked tail.
When hit enough times, he'll fall and the turtle will come back, allowing Wario to process and open the red chest. This will earn the green conch artifact.