In the episode "Fools in April," she has puffy white hair, turquoise skin, and long eyelashes, but no wrinkles. In "Krusty Towers," her first physical appearance, she has light purple hair, glasses, gold earrings, a pink gown and slippers, and looks older. This is also her current appearance.
Mrs. Tentacles seems to like baking cookies as seen in the episode "Krusty Towers." She also appears to be very friendly, although in "Fools in April" she was rude to Squidward in his hallucination. She is married to Jeff Tentacles, although it is presumed that the two are divorced as she appears to live alone and Jeff is shown to be alive in Hooray for Dads!
She makes her first live appearances in this episode because Squidward wants cookies like his mother used to make. After Squidward gets his mother's cookies, Squidward replies "If only Mom was a better cook."