Gremlin

A gremlin as depicted in S1E21

A gremlin is a small, mischievous mechanical lifeform that possibly lived on planet Machina. They are claimed to be the cause of cold-like symptoms in a Metal Cardbot‘s system, causing pranks such as an unstoppable engine or non-functional brakes.¹ Taking advantage of such pranks is said to cause bad luck.²

Gremlins are only discussed in S1E21, Anna's Metal Breath. Some Cardbots, such as Mega Trucker and Buster Gallon, do not believe gremlins to be real creatures.²

S1E21, Anna's Metal Breath (EN dub)
Blue Cop: “Could it be a gremlin?”
Teo and Anna: “A gremlin?!”
Phoenix Fire: “It’s a goblin that lived on Machina planet.”
Mega Ambler: “It could make the Cardbots’ engines unable to stop, or make their brakes not work properly.”
Anna: So that’s what catching a cold means to you.
Mega Trucker: It’s all a myth! I have never even seen a gremlin!
Shadow X: “It’s just we know you have a bad temper!”
↩
S1E21, Anna's Metal Breath (EN dub)
Buffalo Crush: “But… it’s bad luck to get in the way of a gremlin’s trick.”
Buster Gallon: “Wait… do you really believe in such a myth?”
↩ ↩²

Footnotes