The Rotten onion is a special spawner tool distributed by Jagex Moderators to certain players of the Old School RuneScape community. During the MacMillan Cancer Support Charity Event of 2015, it was used to spawn Green banners for players watching the livestreamed event.
There are two unique options for the onion:
- Chew, which would spawn green banners.
- Smell, which would cause the player to say, "Oh Saradomin! Who on Gielinor thought it'd be a good idea to smell a rotten onion?"