Sleep Inducer was a challenge in Annihilation Nation. In this fight, Ratchet had to take on an army of gladiators armed only with the Rift Inducer. To add to the difficulty, Lombax Snooze Mist was sprayed on and on throughout the fight, draining Ratchet's health as he fought on. However, all of the gladiators were susceptible to being sucked into rifts and the challenge was only four rounds long.
- Ratchet & Clank: Up Your Arsenal (first appearance)