This article lists the relationships between Nickel and Tennis Ball.
Episode suggesting a friendship[]
In "PointyPointyPointy ♫", Nickel suggests that Tennis Ball teams with him because he's the same shape and has the same number of limbs as Golf Ball. When they are building the raft on Match's Island, Nickel asks TB if he's sad that GB's gone, to which he replies that he is, but it gave him an opportunity to make more of his own inventions. They successfully complete the challenge in 1st place.
Neutral interactions[]
In "Spore Day", when Coiny tells all of the W.O.A.H. Bunchers to assemble, Nickel tries to go over, though Tennis Ball says he thought they were going to stick together. Nickel asks Tennis Ball what made him think that before going back to W.O.A.H. Bunch. However, since they already had 3 members (Coiny, Pin, Bomby), he was not let into the team, leading him to team up with TB again.
In "Start the Shift", Nickel is trying to get his chunk that is taped to TB's back. Later, Nickel mocks TB while he is explaining the properties of Yoylite. Tennis Ball takes offense to this, but it's unlikely Nickel was malicious. Through some shenanigans, they end up traveling to Getting Teardrop to Talk, You Know Those Buttons Don't Do Anything, Right, and Category One together.
Episodes suggesting a conflict[]
In "PointyPointyPointy ♫", Tennis Ball is annoyed after Nickel teams up with him. Later, Nickel angrily slaps TB after using scientific terms in their lullaby.
In "Spore Day", TB, once again, looks upset after he is forced to team with Nickel, even though it never ended up happening.
In "Respect to the Wicked", After Nickel is kicked from W.O.A.H. Bunch, he asks who wants to team with him, which causes everyone (including Tennis Ball) to back away from him. When Nickel comes back with Fries' trinket, he uses the static electricity from the balloons to destroy Tennis Ball's obelisk, to which he says that he was supposed to tag it, not destroy it. Nickel then jumps down and tags him out.