The Sea Witch is a character who briefly appeared in the "Shrek: Totally Tangled Tales" DVD game. She is a serpent from the classic fairytale, "The Little Mermaid."
Shrek: Totally Tangled Tales[]
In one of the storybook animations, she swims down to visit the Little Mermaid. She presents her with a pair of socks, promising the mermaid legs to walk on the surface.
In the various trivia questions, she is mentioned to have deceived the mermaid into trading her voice for a pair of legs. They were also described to cause the mermaid to feel as though she was walking on knives with each step. Only if the mermaid killed the prince would she go back to her old self if displeased.