Somehow, I'd managed to go 37 years without ever hearing the holiday classic, "I Want a Hippopotamus for Christmas." Written by John Rox, and first recorded by Gayla Peevey in 1953. It is clever and cute, especially when sung by young children (or Redheadlaw7). Here's a taste of the lyrics:

I want a hippopotamus for Christmas
Only a hippopotamus will do
Don't want a doll, no dinky Tinker Toy
I want a hippopotamus to play with and enjoy.

I want a hippopotamus for Christmas
I don't think Santa Claus will mind, do you?
He won't have to use our dirty chimney flue
Just bring him through the front door,
that's the easy thing to do.

And:

I want a hippopotamus for Christmas
Only a hippopotamus will do
No crocodiles, no rhinoceroses
I only like hippopotamuses
And hippopotamuses like me too.

Mom says the hippo would eat me up, but then
Teacher says a hippo is a vegeterian.

Youtube has quite a few versions of the song (e.g. here and here), and there's even a "Hippo Song" FAQ.

Merry Christmas!