The Goon is an especially evil Goon Doc ghoul, seething with dark energy. When it attacks, the Goon has an eerie way of getting into a target Slugslinger’s head. But its thirst for control doesn’t stop there—the Goon is determined to conquer every cavern in Slugterra!
The Goon appears for the first time in Slugterra: Ghoul from Beyond, with a controlled Junjie and some of his marauders to steal Fandango Slugs and to come his army. He is finally defeated by the Shane Gang but succeeds to escape and prepare his revenge. He returns in Return of the Elementals controlling Will Shane, and working with a mutated Blakk and later controlled him to capture and ghoul the Elemental Slugs, but failed and along with Blakk was trapped in the Deep Caverns by Will Shane.
- Ghoul from Beyond (First appearance)
- Return of the Elementals
- Slugterra: Eastern Caverns (Appears in flashback(s))
- Second Chances (Cameo)
- The Fall of the Eastern Champion (Appears in flashback(s))
Moves he has been seen using.
- Protoform Abilities
- Makes people feel ill when standing nearby.
- Emits dark light/energy that allows him to takeover a person's mind & body quicker, and gives them a zombie-like appearance until they're no longer needed. (Darkcloaking without the slinging).
- Can sense the ghouling process from great distances.
- Ghoulgoyle - Hits an opposing slug and uses Dark Energy to transform them into a ghoul.
- Darkcloak (unofficial name) - Hits an opposing slinger and drops them into a temporary coma, while it uses its Dark Energy to takeover their mind & body for its own purposes, and gives the person a zombie-like appearance until they're no longer needed. (This move is a combination of Creepsleep, Ghoulgoyle and Turncloak combined... see Goon Doc).
- The Dark Slinger (Formerly)
- Dark Servants
- The Marauders
- The Emperor
- Shadow Clan (Formerly)
- Dr. Blakk
- Eli Shane
- Kord Zane
- Will Shane
- Shadow Clan (presumably)
- Doc, "The Healer"
- It's unknown if all Goon Docs can do Darkcloaking and sense the ghouling process.
- In Return of the Elementals he is seen working with the Darkbane and Dr. Blakk, plus hosting Will Shane, but it is unknown how he reached the Deep Caverns to ever get to them as the only slug shown to be able to punch a hole to the Deep Caverns is a Tempesto and the Ghouled Air Elemental.
- He is afraid of Doc due to Doc being able to cure ghouls.
- In The Fall of the Eastern Champion, it's revealed the Goon was once a Guardian Slug and was specially trained & tended to by the Shadow Clan and had been guarding at an Eastern Guardian Gate for over 2000 years until The Emperor broke free and corrupted him with his Dark powers.
- He used to be a Guardian Slug before the Emperor ghouled him, however oddly enough it was revealed in Return of the Elementals that he won't transform into a regular Boon Doc. He will turn into a wrinkled up weakened state, and would eventually die, and the only way to cure him is more ghoul energy. A possible reason is that The Emperor ghouled it with so much Dark Energy that Doc isn't able to cure him (like he couldn't cure Dark Water without Fandangos).