Piston

Piston is one of the two newcomers of TUW S1, the second being Mirror. He is a smart character.

Before entrance
He didn't appear in TUW until Episode 11, but he was requested by TheNonLegend in Episode 10, with some detailed information, since Boris liked his idea, Piston ended up being in Episode 11

Blocky Runnings
Piston made his appearance at the end of the challenge, where he and Mirror had to get to the top the quickest, Piston was interested when he first saw the race and managed to get there first, putting him in the World Ending Winners.

Coining The Merge
Piston joins Buzzer and Pluggy's alliance, and then he is the first declared safe after pushing a bush and finding a coin (and a cat, presumably John).

The Platforms Of Hades
Piston knocks Quarter off a platform in the challenge, and he knocks into Icicle. Later, Hanger yells at him for knocking Quarter off, and then they knock each other off.

Kahoot's A Hoot
Piston got second place in the Kahoot challenge behind Buzzer. He got 90 points and was declared safe.

Trivia
Piston is the second character made by someone other than Boris, after Mr. Sardmen.