Urusei Yatsura S01 E04 Mrs. Swallow and Mrs. Penguin

"Grab her horns and she might just become your darling!"

This episode opens with Lum putting on makeup to go meet Darling at school. A swallow swallows some food Jariten gives it and it grows such that it looks like a penguin. It's appearance in school is just the start of a full day of panic.