Based on true events. It's not a lie, but Cocaine Bear is a very straightforward horror/comedy that makes no attempt at being realistic in any common sense of the word. It takes a weird event and makes it even more absurd, and that's what makes it fun. It could've been funnier though.
A bag full of cocaine lands in a forest, where it sits until a bear runs across it. The bear makes a great meal out of it and becomes addicted, if not violently mad. The people who just happen to be in the neighborhood are in for the fright of their life when they cross the bear, who is looking for his next hit.
The characters are pretty over-the-top, everything is played for laughs and the pacing makes sure that whatever joke doesn't hit doesn't linger too long. The weirdest thing though is that the film isn't quite as crazy as it sounds, and the second half felt a bit more pedestrian because of that. Still, good fun, as long as you don't expect the world from it.