The forest is silent, the air still. Not even the leaves rustle. Croog has hunted this ground since he was a youngling and he knows something isn't right. Backtracking a few hundred feet he picks the mammoths tracks back up and ends up in the same spot again. He closes his eyes and sniffs the air, even the beasts scent has gone. Trying not to think about how a Mammoth can just disappear into thin air he carries on into the undergrowth hoping to find another trail to follow.
A few minutes pass and his luck picks up when he finds some hoof prints. Silently he follows the trail out of the forest, through the waist high grass and down towards the lagoon. Spying an Eucladoceros at the water's edge, Croog couldn't believe his luck. Taking it down on his own would be a struggle but not impossible.
Crouching down he sneaks around his prey so he can approach from upwind. Crawling within twenty feet of the creature, his heart is racing from the excitement of the hunt; this adrenaline rush dilates his pupils. In one fluid movement he rises out of the grass and throws his spear.
Before the crudely sharpened flint has even reached its target, Croog is sprinting towards it with his axe raised, ready to finish the job. His aim is true but before he can reach the stricken animal an unearthly roar stops him in his tracks.
Waves from the lagoon come crashing onto the shore. The wounded Eucladoceros tries to escape but is snatched up by a claw that dwarves it.
Croog watches dumbstruck as his prey is taken from him and eaten whole.
The behemoth emerges from the water. It doesn't notice Croog, or feel him as its foot comes crashing down on him, squashing him like a bug.
All it knows is hunger.