From Wikipedia: "A funny animal is an anthropomorphic animal character who lives like a human. They are typically bipedal, wear clothes, live in houses, drive and ride vehicles, and have jobs or may even be recognized citizens of countries, which distinguish them from other animal characters who may nonetheless display anthropomorphic characteristics such as speaking or showing facial expressions."
Snoopy is often portrayed doing these things, but they are all fantasies. However...
...in fantasizing about living as a human, he displays human-level intelligence and emotions.
Also, many comic strips make it unclear how much of Snoopy's human-like behavior is in his mind. Sometimes the other characters are aware of his fantasies, or, especially, watch him go about his business on two legs.
Yet he still lives in a dog house in Charlie Brown's yard.