LIMERICKS are poems with five lines with a special beat and rhyming pattern:
Lines 1, 2 and 5 have 9 beats and the last words rhyme.
Lines 3 and 4 have 6 beats and rhyme with each other.
Here's a fun limerick from Sue Ellen:
Limerick by Sue Ellen
There once was an old man from Peru
His poor llamas came down with the flu
In the valley he passed
All the people who gasped
At the beast that was uttering "moo"