- Maggie Pesky: In "Love Stinks," Melvin thought Maggie was in love with him, because she defended him against some bullies. Later, Melvin wanted to go on a date with Maggie at the Stickyfeet Swamp Club. Maggie just wanted to be friends, but Melvin thought they were a couple. Maggie later told him she wasn't his girlfriend.
- Gym Shorts Kid: Melvin and Gym Shorts Kid has a friendly relationship, as seen in "The Usual Insects".
- "Love Stinks" (first appearance)
- "The Usual Insects"
- "Best Best Friends"
- "Club Hopping" (cameo)
- "Roach Hotel"
|The Peskys and relatives|
|Maggie Pesky | Aldrin Pesky | Pupert Pesky | Bella Pesky | Chauncey Pesky | Frieda Pesky | Florence Pesky | Zeb|
|Buzzdale Academy staff and students|
|Rayna Cartflight | Dawn Swatworthy | Maria Monarch | Lacey Ladybug | Eugene and Wendell | George | Ruben "Gym Shorts Kid" | Snapercival Carpenter | Melvin Stinkelton | Chip | Lefty | Lukas | Principal Peststrip | Mrs. Wingston | Cornelius Bugspit | Mrs. Lunchlady | Nurse Hatchison | Troy|