Why Can't the Animals Smile?

"Why Can't the Animals Smile??" is a song featured in the 1968 Rankin/Bass Christmas special The Little Drummer Boy.

Lyrics

You never heard a lion laugh.
You never saw a gator grin.
A goose in a gaggle never gives a giggle.
Why can't the animals smile?

You never saw a smiling frog;
a tickled lamb; a happy hog;
a light hearted camel;
a merry old mammal.
Why can't the animals smile?

A barrel of monkeys;
A pack of silly donkeys;
An elephant; A caribou.
Have never been heard,
to chuckle a word,
or twitter like people do.

You never heard a mouse guffaw;
a crow that did much more than caw.
Is an eagle, too regal?
Or is it all illegal?
Why can't the animals smile?
Why can't the animals smile?