In 0 BBY, as a revenge for Jabba's coup for the Holiday Towers, he stole the droid CZ-3 while staying as a guest at Jabba's town house in Mos Eisley. His intentions were to take revenge on Jabba by gaining access to the secrets hidden in the droid. However, Jabba had foreseen this eventuality, and CZ-3 was spying on Mcgrrrr. The entire operation turned out to be a sting operation set up by Jabba.
This plan was foiled because the Jawa Aguilae and her partner, the Squib Macemillian-winduarté, stole the droid from him (or, as they would claim, found or bought it after it malfunctioned and went wild). Mcgrrrr, infuriated, sent his Jenet henchman Tols Vengra after the droid.
Vengra found the droid at the same time that Jabba's bounty hunter Takeel did. While they were arguing, Takeel's brother Zutton shot and destroyed the droid. However, in the process, CZ-3 had provided Jabba with enough evidence to expose Mcgrrrr and Vengra's plots against Jabba.
Mcgrrrr's appearance was based on Declan Mulholland, the actor who played a Human version of Jabba the Hutt in a scene of A New Hope. Mulholland wore a similar costume in the movie Time Bandits.