Cannibalism is actually quite common among wolf packs. Wolves are known for being opportunistic predators and carnivores, so they have no problem with eating one of their own as a meal. They sometimes feast on the sick or injured in the pack.
Wolves can easily reach up to 200 pounds at a time, shockingly enough. The largest domesticated dog barely reaches that impressive number. The biggest was killed in Alaska back in 1939, and it weighed 175 pounds. Ukraine has even larger, though.