From Creatures Wikia
The Hakuna Matata is a log (inspired by the movie The Lion King) filled with grubs (food), worms (fruit), and ants (nuts) for your creatures to eat. The grubs, worms, and ants disappear after a short time, so you don't have to worry about wiggling food underfoot. This agent was made by TwilightCat (and probably with sprites by Bug) and can be found on TwilightCat's website.
Did you know? The readme has the entire Hakuna Matata song in it!