Monitor lizards, large and sometimes fearsome lizards common throughout
Africa, the Indian subcontinent, Southeast Asia, and Australasia, aren't
just big and scary: they're also among the fastest learners in the
reptile world. Monitor lizards have been proven to be able to count--not
just know which of a group has the highest number of objects, but to
know exactly which that number is. (You can read more about that
experiment here.)
Source: Here
read more "Reptile: Monitor Lizard"
Source: Here
