! Goblin's Gold
[[SealedEvilInACan Merlin releases a trapped goblin]]. HilarityEnsues.
* BluffTheImposter: Arthur does this with the possessed Gaius, only to be immediately knocked out afterwards.
* CringeComedy: The goblin covers Sir Leon in boils, gives Arthur donkey ears, makes Uther's hair fall out, and forces Morgana and Gwen to break wind in front of the entire court.
* CuriosityIsACrapshoot: Should have just left that box alone, Merlin.
* CuriosityKilledTheCast: A non-fatal example, when Merlin releases the goblin.
* FantasticArousal: Arthur's reaction when Guinevere begins to stroke his donkey ears.
* ForTheLulz: The goblin's only motivation (outside of accumulating gold).
* [[DemonicPossession Goblin Possession]]
* LetUsNeverSpeakOfThisAgain: Arthur suggests this to Gwen. She's very receptive to the idea.
* OurGoblinsAreDifferent: Small and vindictive.
* ScrewPolitenessImASenior: The Goblin-in-Gaius gets away with a fair bit of bad behaviour thanks to this trope.
* SealedEvilInACan: The goblin, who was sealed in a box, then escaped to torment everyone in the castle, and then resealed after being trapped by Merlin and Gwen.
* TastyGold: A variation. Goblin-in-Gaius doesn't lick gold to check its authenticity, but because it tastes good.
* TattooedCrook: The goblin has multiple tribal markings or tribal tattoos of what appears to be the sun.
* TheTrickster: The goblin.
* UnusualEars: Arthur temporarily gets donkey ears.
* WhatHappenedToTheMouse: Merlin finds the trapped goblin in a secret room behind a bookcase in the library. It's filled with magical books and paraphenalia, but he never revisits it and we never learn anything more about it.