Underground Ernie is some so-called "jolly good", atrocious-looking bloke who is in charge of a large amount of underground metro systems located in the UnWorld. Nobody really knows for certain how he remains in employment up to the present time considering he's so much of a crackhead that he can't even tell the difference between the underground and the overground, as if there's even such thing as that.
Ernie was often prominent for his work in the undergrounds, so prominent in fact that he received a TV series based and named after him. It was released in 2006, and during production they nearly lost everything not once, but three times! People despised and feared his show mainly due to how the sentient locomotives that often accompanied Ernie resembled that of as if they were thrown into a junkyard, forced to smoke crack and then stapled back together loosely. Because of this, the show only ever lasted one season composed of twenty-six episodes. Ernie wasn't happy with the reception of his series and that it was short-lived, though he has plans to bring his show back, and plans to make it even creepier than the original.
Some people have pointed out the similarities between Ernie's series and Thomas the Tank Engine, in that both series feature anthropomorphic locomotives. Despite that most of the locomotives are underground metro trains, they often travel over ground through the open countryside to various stations, including a seaside resort, completely going against the entire show's motive.
Underground Ernie temporarily lived in the sewer fish land, where fish was there. He ate the fish after he UnPoisened it, in which he made a fish shop and guess what? He got money, all types of fish, went out of the sewer, and hugged an fish. He survived 😌. A guy named Fanny hates this person, which is uncommon for ernie to hurt her. In 2017, Ernie made a film called Ernie of the Underground, and it was questionable to say the least.