Klaus Heisler is the Smith Family pet on American Dad!. He was once an East German Olympic ski-jumper until his brainwaves were switched with that of a goldfish in the 1986 Winter Olympics by the CIA to prevent him from winning the gold medal.
The entire Smith family from American Dad appear as part of a cold-opening for "Bigfat", with the scenes that were originally intended for "April in Quahog". When the Griffins greet their new neighbors, the Smiths, who moved into Cleveland's old house, Peter sees Roger. Stan tries to keep Peter quiet but is forced to have to kill him as he starts to tell Quagmire about the alien. The entire opening turns out to be a dream by Hank Hill.
Klaus is voiced by Dee Bradley Baker.