What form of poetry is defined as humorous verse with a rhyme scheme AABBA?

The form of poetry you're describing is called a limerick.

Here's a breakdown:

* Humorous verse: Limericks are known for their lighthearted and often silly nature.

* Rhyme scheme AABBA: This is the defining characteristic of the limerick. The first, second, and fifth lines rhyme, as do the third and fourth lines.

Let me know if you'd like to see an example!