Thanks to Edward Lear, there's no shortage of limericks for children. This recent small collection is part tribute to Lear and part homage to the verbal play of Seuss's Fox in Socks. To wit:
Which Witch Was Which?
Two witchy witches in a Wichita ditch,
One witch with a twitch caused the witches to switch,
The spell they were under,
Caused people to wonder,
Which Witchita witch switched was which?
There's even a Twimericks website.
from Twimericks: The Book of Tongue-Twisting Limericks by Lou Brooks. Workman Publishing, 2009.
(Note: when quoting poems online, always include a full citation for the collection from which the poem originated. If the poem is not in the public domain (i.e. is still in copyright) abide by the principle of Fair Dealing in your use of the work.)