Celtic Guardian is one of the most commonly used monsters of Yami Yugi's Deck. A running gag that happens throughout the series is when Yugi Summons him, he replaces the adjective "Obnoxious" with a different one. Another ongoing joke has the Guardian reference the adjective in some way upon being Summoned or prior to being destroyed. (e.g. "I'm so bamboozled.") He apparently has a grudge against the Blue-Eyes White Dragon for spreading to others that he is a "weak monster", and has developed a complex as a result of that. In a rap battle between Yugi and Jaden Yuki, it is revealed that his name is allegedly Dave, and that he had difficulty stringing together coherent rhymes.
|"Yami of Darkness"||Frustrated||"I am so frustrated."|
|"Dirty Dueling"||Bamboozled||"I'm so bamboozled."|
|"Penguin Ex Machina"||Agnostic||"I'm not sure what I believe in."|
|Cr@psule Monsters 3||Passive-Aggressive|| "God, I wish some people would stop posting on Facebook about cats all the time."|
"Wait, what? Who's doing that?" (Yami)
"Oh, you know. Lots of people."
|Throw Haga From The Train||Sexually Frustrated||"I'm so sexually--oh f*ck, I'm on a train!"|
|Right In The Feels||Brainwashed||"I'm so whatever he just said!"|
|Valley of the Duels||Obnoxious Celtic Punching Bag||"I'm so..." (cutoff)|
|YGO Kiwami||Obnoxious Kill-Stealing||"That's a nice kill you've got there. It'd be a shame if someone stole it."|