The ghost had a skeletal head and arms, a jagged mouth, and glowing yellow eyes. He wore a white hat and matching jacket with torn sleeves and a yellow nametag (with no name on it) on the left side. He did not have legs; instead, his body ended with a ghostly tail. He carried a dog catcher's net.
He was determined to get the Doo family collar, declaring "That collar is MINE!"
Powers and abilities
He floated in midair somehow.
Buster McMuttMauler was a dog catcher gone bad. He antagonized a small puppy, which invoked the wrath of Scooby's parents. They chased him into the back of his own truck, where his boss confronted him for stealing dog collars. Buster swore revenge, claiming he would come back for the Doos and their collar.
A Pup Named Scooby-Doo
It was the day before Scooby-Doo's birthday, and he got the family collar as a present (which he hated). When the bell rang at the Knittingham Puppy Farm, Shaggy Rogers and Scooby-Doo went to answer the door. They found a huge present, which was supposedly for the Doo pups. However, the "present" turned out to be the ghost of Buster McMuttMauler. He demanded the collar, prompting Shaggy and Scooby to run and hide. The ghost snagged Mrs. Knittingham with his net and kidnapped her. The gang set out to look for her.
Shaggy and Scooby decided to "search the kitchen for clues" and devoured everything in the refrigerator. However, the ghost appeared, once again demanding the collar. Shaggy and Scooby fled into the bathroom and escaped out the window. The Doos attempted to sniff out Mrs. Knittingham, and they found the ghost's net outside Dr. Needlemeyer's office, along with the ghost himself. The gang ran back into the house to escape him, but he broke the door down and dognapped Scooby's parents, causing Scooby to literally turn white and fall to pieces.
The kids return to Dr. Needlemeyer's office to search for Scooby's parents. Shaggy said to keep it down so that the ghost wouldn't find them, but it was too late for that; he already did. Scooby tried to stand up to him, but the ghost was not intimidated. He chased the gang around until Velma Dinkley blew a dog whistle, summoning a group of dogs which chased the ghost away.
The gang tried to trap the ghost by using the collar as bait tied to a fishing pole and luring him onto an X panel, which would've caused a doghouse to drop on him. However, the trap backfired when the ghost managed to catch the collar with his net. He yanked the line, causing Scooby to fall into his clutches and Shaggy to get caught in the trap. The ghost used Scooby's tail as a spring and sent him flying high into the air. Scooby landed on the ghost and flung him in between two tires, capturing him. Velma unmasked the ghost to reveal that the culprit was... a hand? She removed more of the costume to reveal Mr. Trixenstuff. He wanted to steal the Doo family collar because it was worth a lot of money. 
- Catcher on the Sly would later show that Buster McMuttMauler was actually still alive.