Planet Janet is a character and planet that appears in the episode, "The Lonely Planet".
Janet is a nice planet that however tried to force Wander and Sylvia apart vehemently angrily.
Janet used to like Wander in a "love" way. She tried to force him and Sylvia away from each other and she trapped Wander in a cottage and tried to kiss him, until Sylvia came along and punched her, so it was revealed that she wanted a friendship like Wander and Sylvia.
Janet used to hate Sylvia and forced her and Wander away from each other by making a slur of obstacles.