Mack and Diesel are characters from Disney's 2002 movie, Snow Dogs. They are strong, powerful, and well trained sled dogs. As part of the middle of the sled dog team, its up to them keep the pace and pull the weight of the sled. They also ensure that Scooper and Duchess, keep the the same pace, nipping them when they need encouragement.
Talking Mack and Diesel and the other talking dogs at the beach in Ted's crazy dream
Mack and Diesel and the dogs at Ted and Barb's Alaskan wedding