An alligator can go through 2,000 to 3,000 teeth in a lifetime.
268
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
Sharks, like other fish, have their reproductive organs in their chests.
248
Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14
The seahorse is the only fish to have a neck.
12
The sound of a tiger's roar can travel a distance of up to 2 miles (~3 km).
255
When the "Elephant Whisperer" Lawrence Anthony died, a whole herd of elephants arrived at his house to mourn him.
25
A koi fish, named "Hanako", was owned by several individuals over many years and lived to be 226 years old, dying in 1977.
6