A koala is sitting in a gum tree smoking a joint when a little lizard walks past, looks up and says "Hey Koala! What are you doing?"
The koala says, "Smoking a joint, come up and have some."
So the little lizard climbs up and sits next to the koala and they have a few joints. After a while the little lizard says his mouth is dry and he's going to get a drink from the river. However, the little lizard is so stoned that he leans too far over and falls into the river.
A huge crocodile sees this and swims over to the little lizard and helps him to the side, then asks the little lizard, "What's the matter with you?"
The little lizard explains to the crocodile that he was sitting smoking a joint with the koala in the tree, got too stoned and then fell into the river while taking a drink.
The huge crocodile says he has to check this out and walks into the rain forest, finds the tree where the koala is sitting finishing a joint, and he looks up and says "Hey you!"
So the koala looks down at him and says:
"F**k dude... how much water did you drink?!"