Smelly Onion is a crying half slice of red onion. He has crossed eyes with tears coming out of them.
- Smelly Onion is similar to, and shares a name with Smelly Onion, a Trashie from Series 3 of the Trash Pack.
- He is the second onion Grossery, after Onion Scum.
- He is depicted with white eyes in his static art, while his figure depicts him with yellow eyes.
- He and Cruddy Cream appear on the bottom right corner of the Series 2 large packs.
- His static art portrays him as red, while his figure and catalog art have him as purple.
| Series 1|
Rotten Raspberry / Grimey Lime / Shiverin' Spider / Frost Bit Wasp / Frosty Fly / Cold Cockroach / Mushy Slushy / Horrid Hot Dog
Smelly Onion / Horrid Hot Dog
Crapple Core / Trash Block / Wash Out / Grot Sock / Blow Fly / Trash Head / Vac Attack