Grandpapa "Susan" Acachalla is the father of Papa Acachalla, Jeremy Acachalla, and Papa Nadachalla, the husband of Gramama Acachalla, the uncle of Maxwell Acachalla, the possible brother or brother-in-law of Mary Fart, and the son of petrified Grandfather.
Grandpapa lived in a house with his sons, Papa Acachalla, Jeremy, and Papa Nadachalla, and his maid/nephew, Maxwell (whom he didn't know about but only knows that he removed Baby Papa Acachalla's left arm).
Grandpapa had a quick temper and little patience for Papa's tomfoolery. He shouted quite regularly, especially because he couldn't get him to say "This is Sparta". He showed little to no concern for Papa's safety, asking him to test his warrior abilities by jumping headfirst through a window and fighting an Allosaurus. However, he showed great pride when Baby Papa Acachalla reached his final form: Baby Tank.
Grandpapa did not retain the large ego of his son, rather he pushed these ideals on his next of kin.
- Sue Acachalla may have been named after him.
- He was originally from Russia like his wife Gramama Acachalla.