A banana slug can be 6-8 inches and their erect penis can be just as long. Also, their penises emerge from their heads. After sex, banana slugs eat each others penises.
17
When a male gentoo penguin "falls in love" with a female penguin, he searches the entire beach to find the perfect pebble to present to her.
25
Camels and llamas can cross breed. The offspring is called a ‘Cama’.
10
Vampire bats adopt orphans, and are one of the few mammals known to risk their own lives to share food with less fortunate roost-mates.
402
The elephant brain weighs about 6,000g.
274
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
Cats and dogs can hear ultrasound.
350
In 1955, the citizens of São Paulo were so upset with their government that they elected a rhinoceros named Cacareco (meaning rubbish) to the city council in protest, with over 100,000 votes.
18