Mark

Mark is a teenager with reddish-brown hair and pink skin. He is tall and slender. His face is thin, with a pointed chin, slanted eyes, and a pert nose. His hair is messy, and his bangs are parted. His eyebrows are arched.

Mark wears a burgundy hooded cloak with a skull brooch. Underneath, he wears a black t-shirt with a yellow Planeswalker symbol from Magic: The Gathering, blue jeans, and large gray boots. He also wears black-framed glasses.

Mark is direct and condescending when interacting with people and speaking in general. He often speaks very formally, but without regard for others' feelings. He is apathetic and inadvertently orders, yells, and insults people. While his behavior is antagonistic, he has proven helpful when asked, and he is often seen playing games and hanging out with friends. He is also shown to be dishonest in episodes such as "Kelsey's Adventure," when he doesn't pay Jerry for the movie tickets he bought himself, or when he hides when Kelsey fights Jerry.

Craig, Kelsey, and JP are trying to figure out how to end a game of tag, so Craig takes them to the old rock to talk to the creek elders. Once there, they call the elders over, and Mark watches and asks what they have to offer. They present junk food, and Mark grants them permission to enter.

They enter, and Barry, David, and Mark introduce themselves. Mark asks what they need but tells them to hurry up since they're in the middle of a game campaign. The teens are stunned when they're told the kids are talking about Tag. Mark explains that the game has been going on longer than they've been at the Creek. They argue about who started the game, and Kelsey claims she's "it" now. The teens are alarmed, and David flips their game table over, yelling that Elder Rock has been compromised. Kelsey explains that she just wants to end the game, but Mark insists it has no end.

Later, Mark is seen yelling at Kit at the Trading Tree because she won't accept his bitcoin. Meanwhile, Bernard comes running through their group, pushing the teenagers to the ground as Kelsey chases after him, threatening to cut off his head if he doesn't let Craig tag him. Kelsey proceeds to jump over them one by one to get to Bernard. Once Craig tags Bernard and JP announces to everyone that the game is over at the Creek, the elders applaud along with a crowd of children.

Craig is going to play a card game called Bring Out Your Beast. Craig arrives to find Mark telling Turner he won't face her because he needs new cards. When Barry points out that Mark has to fight her according to the rules, he forces him to. Craig and the other kids watch as Mark easily defeats her.

Later, Craig and Bernard return to the scene where Kelsey and JP approach them and tell them that Turner has Bernard's card, Beast's Lasso, and that she has been challenging and defeating everyone with it. They overhear Barry encouraging Mark to defeat Turner, saying that Mark is the last card fighter left. Shortly after, Turner defeats him. The creek elders discuss the battle with the other group of spectators, and Turner is finally defeated. Everyone applauds before dispersing from the area.