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 is going to get a drink from the river. But
the little lizard is so stoned that he leans too far over and
falls into the river.

A 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 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:   
"DAAAAYYUM dude ... how much
water did you drink?!!"