Rookie first appeared in "Bandoleer of Brothers" when the Shane Gang responded to a distress call and took back a small town. Rookie then followed Eli and the others to a fortress wall, using his unknown ability. At first Rookie thought he was useless but soon discovered the nature of his ability. This lead to him bringing down the stronghold wall, however Burpy was captured in the process via a Attacknet. While the rest of the gang was fighting a Darkbane with a gattler, Rookie managed to free the other Slugs. Afterwards he was welcomed as a new member of the Shane Gang. He was also used in "Dark as Night" to blow up some of Dr. Blakk's Titan Tanks.
In Slugterra: Ghoul from Beyond, he was "swallowed" by Goon but burst his way out.
- Protoform Abilities - By pressing the "lever" on its head, it can remotely detonates mines it has deployed.
- Mineblaster - Releases multiple mines, which it can then detonate remotely once back in protoform.
- Bandoleer of Brothers (First appearance)
- Dark as Night
- Light as Day
- Slugterra: Ghoul from Beyond
- Slugterra: Return of the Elementals
- Slugterra: Eastern Caverns
- The Lady and the Sword
- Slugterra: Into the Shadows
- He could be seen seconds before his formal appearance when everyone is cheering for the Shane Gang when they arrived.
- He use to be owned by a kid before he was given to Eli in the effort to stop Blakk's plan to kill/ghoul the Cavern.
- Rookie might be a child, due to the fact that he had never been slung before joining Eli, and that he never knew what his own "veloci-morph" abilities were.