Iconic character in the Peanuts franchise. Snoopy is Charlie Brown's pet dog, a white beagle who is somewhat anthropomorphic in that he verbalizes his thoughts through speech bubbles rather than words. Somehow the neighborhood kids understand him, and he has been treated as more human than dog.
Snoopy has become the official mascot of the Apollo Program and aviation in general due to his refusal to accept defeat; in the comics, he sends typescripts to publishing companies only to have them constantly rejected, and he likes to pretend that he's a World War I pilot fighting against the Red Baron in his 'Sopwith Camel' fighter plane (a.k.a. his doghouse).
