Bernie is an old shopkeeper in TMNT.
In Dreams: Bernie was a physicist who wanted to prove that our dreams take place in another dimension. But his dream portal went crazy trapping the alien Dream Beavers in his mind! So who ever gets close to Bernie shall be killed by the Dream Beavers! So Bernie moved far away in Northampton and never slept for 40 years. When the Ninja Turtles moved to Northampon they too were attacked by the beavers! Casey saved the day when he broke the device that was keeping the beavers in the dream dimension. When Bernie finds out that the Dream Beavers in the real world are just regular beavers he sees that he was staying awake for 40 years for nothing. So he passes out, and Donnie and Casey take him back to his drugstore.