Buyon

Buyon (ブヨン) is a giant round bellied pink monster that lives inside of Muscle Tower. The creature is General White's secret weapon and possible pet. His name is a play on the word "Bouillon", a type of broth, which has a root from the word "boil" (possibly to display the irony of his defeat when he is frozen solid).
Buyon is the hideous, blubbery pink tenant of Muscle Tower's fifth floor, only accessible via a trapdoor on the sixth. Initially, Buyon appears to be a seemingly indestructible threat to Goku and Android 8 when they fall through the trap door and encounter Buyon. Every technique Goku uses against him, from a Kamehameha to the belly or a kick to the face, is bounced back effortlessly by Buyon's lard. The monster can also cast electrical blasts from his antennae. Buyon apparently feeds on cattle supplied by his keepers, and even comes close to devouring Goku and Android 8 during the encounter.

Through a long and tiring process, Goku eventually realizes that Buyon is susceptible to the cold, and after Goku knocks a small hole into the wall, Buyon is frozen solid. With this, Goku strikes the monster with a hard enough punch to shatter him into pieces.

Apparently, Buyon was well known by the Jingle Villagers, as they heard stories about a creature lurking within Muscle Tower and worried for Goku's safety as a result.

Information from:
http://dragonball.wikia.com/