Hey, Who's in the Loo?

Bear really needs the look, but it's otherwise engaged! Who's taking so long, and why? Bear can't hold out much longer, he's desperate, but the door is locked and the toilet is occupied. He is soon joined by Pig, Elephant, Tiger, Penguin, Monkey and Giraffe who are all need to go too! Who is in the loo and why are they taking so long?