Brian encountered a Bear because he was searching for food and he suddenly saw berries and the bear eating it so the bear looked him right in the eye and the bear shared him his food. The bear was as long like an SUV and had sharp teeth like razors.
Brian encountered a porcupine while he was sleeping and he got stabbed with the porcupine's quills because Brian cant see where the porcupines was. Brian was full of pain in his leg and he tried pulling the quills and he succeeded.
Brain encountered a fish when he was trying to catch a fish on the lake with his spear. Brian’s plan didn't work because the fish were too fast for him so he had an idea that he needs to make a bow and arrow.