1. Someone who feels more comfortable in the presence of animals or beasts, than in the company of humans.
2. An individual with animal instincts or traits; or one who demonstrates attributes which are usually exhibited by wild animals.
3. Someone with the ability to talk to animals.
1. My friend Thomas would rather stay home and play with his pet iguana than go out to the club and pick up girls. He's a regular animal boy.
2. Did you see how that man ate his steak? He ate the whole thing with his bare hands. He must be an animal boy.
3. Your friend can speak to animals? What is he, an animal boy?