The seahorse is the only fish to have a neck.
12
Sergeant Stubby was the only war dog to be promoted to sergeant through combat in WWI. He saved his regiment from surprise mustard gas attacks, found and comforted the wounded, and even once caught a German spy by the seat of his pants, holding him there until American Soldiers found him.
16
Denmark has twice as many pigs as there are people.
66
Alligators can live up to 100 years.
337