Plaxum is a mermaid-like alien and ally of Lance in season 2 of Voltron: Legendary Defender.
She was voiced by Mae Whitman. who also voiced Shanti from The Jungle Book 2, Tinker Bell, Rose Killdragonosa from American Dragon: Jake Long, April O'Neil from Teenage Mutant Ninja Turtles (2012 series) and Katara from Avatar: The Last Airbender.
When space became a big worm monster who brainwashed her and her friends, Swirn and Blumfump's people, Plaxum, Swirn and Blumfump put their heads to hide their brains jellyfish. When they rescued Lance, they asked him for help to rescue their people, and Lance agreed to help. At first they did not know what caused the brain-washing, but later Lance and Hunk reported that reason was the worm monster's produced food. When their people was saved, Plaxum took out a jellyfish and Lance fell in love with her.