<P> Later , the animals hold a meeting saying that they think Griffin is the best zookeeper at the zoo and do n't want him to leave , so they decide to find some way to help him win Stephanie 's heart . Jerome the Bear ( Jon Favreau ) suggests that they teach Griffin their animal mating techniques , but Joe the Lion ( Sylvester Stallone ) protests , reminding them that it 's against the animal code to talk to humans . Donald the Monkey ( Adam Sandler ) says that Stephanie will be at the zoo tomorrow , and all the animals have to do is make Griffin look like a hero in front of her . </P>
who plays the lion in the movie zookeeper
Sylvester Stallone