Butkus was a fawn colored Bullmastiff.
Butkus's role in Rocky and Rocky II
In the 1976 film, Rocky, Butkus lived in a cage while waiting to be sold at J&M Tropical Fish. Rocky Balboa displayed a lot of love and affection for the dog as he would usually yell "Yo, Butkus!" and make animal noises during his routine visits. Butkus was later given to Rocky by Adrian as a Christmas gift to keep him company while training for the Heavyweight Championship of the World. Rocky and Butkus were later seen running down the street together on their way to the meat plant where Paulie Pennino worked. After noticing a news truck parked by the plant, Rocky left Butkus on the street to wait for him while he went inside to satisfy his curiosity. Butkus is not seen again for the rest of the film.
In Rocky II, Butkus is once again seen as Rocky's pet. He is first shown in Rocky's old apartment, along with Adrian, just after Rocky's marriage. In the scene, Rocky tells Butkus to move as he and Adrian want to lie down after a long walk downtown. Butkus is often seen in other parts of the film with Rocky giving him a bath or petting him. Rocky talks to Adrian about Butkus. One scene in particular has Rocky describing Butkus as having a different look than an average dog as though he is special in some way. Afterwards, Butkus is not seen again for the rest of the film nor in any following sequels.
In Rocky Balboa (the final instalment) a different dog, who is given the name Punchy after being adopted by Rocky and Steps, seems to serve in the same role that Butkus did. Much like Butkus in the past, Punchy is seen running with Rocky to keep him company. Punchy, like Butkus, is neither mentioned nor seen for the rest of the film after Rocky trains with him.