He is Morgana's gigantic tiger shark who loves intimidating others with his size.Undertow is summoned by Morgana and is used as a threat to eat baby Melody if Triton doesn't hand over the trident. King Triton, who turns Undertow into a mini-fish, such as a piranha. Undertow complains to Triton about this, it doesn't work. So, he leaves with Morgana and her two manta rays, Cloak and Dagger.12 years later, at Morgana's lair, Morgana's attempts to turn Undertow back into a shark fail.