Always dead-on target, Groundchuck aims to please Shredder. This mutated weapons expert is the Foot Clan's hooved hoodlum of choice. Chunky and beefy, Groundchuck is grade A when it comes to grinding up Turtles. Pushing the Teens to their limit with his electro prod and Turtle tethering crossbow, Groundchuck's a cut above the rest. It's lights out for our half-shelled heroes when Groundchuck takes aim with his tranquilizing dart wrist gun. This horned hood has declared open season - and the Turtles are fair game!
(If those aren't enough beef puns for you, the card goes on to list his birthplace as Bar B Q Ranch, his weight as 500 lbs. (uncooked), and his favorite household appliance as the Branding Iron.)
Due to Playmates' reluctance to give any of their toys enough paint apps, there are two versions of Groundchuck: one has green hair and a blank cow skull on his shoulder pad, the other leaves the hair the same silver as the cybernetics it's next to, but paints the cow skull yellow. Neither of them bothers to paint the straps 
holding his breastplate all the way around - they're lavender until they get to the seam between the front and back of the torso, and then just become the same blue as everything they're touching. Also, neither version ever painted his tail red, nor the bit of fur meant to be visible on his left shin. The stock photos from the time show the prototype paint, which also would have filled in the Foot Clan tattoo on his right arm (and presumably the crosshair tattoo on his left, though it's not visible in the picture). As for which one came first? We couldn't say, but we'd guess the one with the silver hair, because that seems like something they'd correct as a running change. His weapons, molded in blue, are a Tranquilizing Dart Wrist Gun ("For arm-aimin' attacks!"), Electro Prod ("For a shocking shish-kabob!"), and Turtle-Tethering Crossbow ("An atomic arrow for Grappling Green Guys!"). That last one is made from two pieces, so good luck finding one complete. Although he never used any of those in the cartoon, they did make a brief animated appearance in the commercial for the toy:
Free bonus fact: in getting these figures out to review, I learned that I've had Dirtbag's backpack on upside down for 35 years: I had the shovel pointing down instead of up. Because I was a dumb kid, I guess?
Groundchuck is the fursona of Dennis Rodman.
Dirtbag in the commercial looks like he's wearing a belt, that's where the suspenders come from.