Mr. Boopkins, also known as Joe, is a minor character in the SMG4 series.
In terms of personality, Fishy Boopkins' dad will always be hostile towards those who torture his son. However, he can also be helpful, such as sending people to where they need to go.
He is the father of Fishy Boopkins and JubJub Boopkins. He is a massive sea monster sporting a blue suit, a red tie (both similar to that of Octodad's), and also possessing two enormous tentacles that can destroy just about anyone or anything in his path.
In SMG4: Mario and the Experiment, Fishy summons his dad to take down Godzilla. However, he proves to be a much more difficult opponent than what he normally faces. Thanks to Mario unintentionally launching himself out from the cannon and grappling Godzilla, Mr. Boopkins wins.