The 1st episode of the 18th season of Arthur.
The episode begins as Arthur talks to the viewer about Project Z Zone. He presents an example in a show called The Altos. Whenever an Alto say something, it is replaced with a random word from the game. Arthur then says that it's not used in real life, but he claims it could be fun if it was.
After the title card is shown, D.W. goes to the crystal shop with Grandma Thora. She overhears a teenage boy arguing with his mother, and when he calls his mother a "Hadouken", she drops the vase she is holding and turn into ices.