What is it?

What is it I wonder asked Jay, wielding his glass
The tracks go round here said Pete, on the grass
It looks like a brontosaurus
Or maybe, it’s a rhinoceros
Let’s get down for closer study
Down knelt Jay and his best buddy
Maybe a wolf or a tiger
Maybe a lion or a panther

And as the boys swapped ideas aloud
The ground seemed to darken, as if by cloud
The boys rose slowly off the ground
And turned their heads slowly around
To see a large brown shape
With shiny teeth in mouth agape
It wriggled its dog like snout
Both boys gave a fearful shout

Exit two boys
Pursued by a bear