Kermit, Rowlf, and to a lesser extent Crazy Donald (Harry) remained among the core group of Classic Muppets. George and Mildred were featured heavily in Muppet Show's first season but quickly faded to background character status along with Droop, Miss Mousey, and Thog. Some Muppets went onto the Muppet Show in different forms; Rufus became Muppy, Crazy Donald's name was changed to Crazy Harry, and Brewsters was turned into a wise guru character usually seen in the first season's panel discussions. Crazy Donald was based on Muppet designer and special effects guru, Don Sahlin, who had a habit of frightening members of the workshop with various riggings, gags, and yes - even explosions. He once blew up Dave Goelz's desk!