How big is the tiniest animal in Lion King?

The Lion King doesn't explicitly state the size of the smallest animal. However, we can make a good guess based on the animals that are shown:

* The smallest animals shown are insects: Like the ants that Simba and Nala encounter in the "I Just Can't Wait to be King" song.

* Real-life ants are tiny: They can range in size from a few millimeters to a centimeter.

Therefore, it's safe to assume the smallest animal in the Lion King is about the size of a real-life ant, a few millimeters to a centimeter.