Cassie is a cat that first appeared in "New Friend on the Block." She is a gray cat who wears glasses with gold frames and cyan lenses (and no earpieces), a white hat of some sort, a pink dress, and red leggings.

Cassie appears in "Practice Makes Perfect," revealing that she attends the same school Huckle and Lowly attend and has Miss Honey for her teacher, likewise.

Then she appears in "The Sleepover" as one of Sprout's guests.

Again, she appears in "The School Dance" as one of those attending the dance, ultimately dancing with a reluctant Huckle, and in "The Winners," as one of those joining the race.