What is hidden in 3D image?

A koala was sitting in a tree smoking a joint when a lizard walks up and says "Hey koala what are you doing?"

The koala answers "Smoking a joint, come up and have some." The lizard climbs up and the two share the joint.

After a while the lizard says his mouth is dry and excuses himself to a nearby river to have a drink. The lizard, so stoned, leans over too far and falls in. A crocodile swims out to rescue him. When they get onto dry land, the crocodile asks, "What's wrong with you, lizard?"

The lizard tells him that he was smoking a joint with a koala, and he got too stoned and fell in while taking a drink. The crocodile has to see this for himself, so he asks the lizard to take him to the koala.

When they get back to the tree, the crocodile looks up at the koala and says "Hey, you."

The koala looks down and says "Shiiiit dude, how much water did you drink?"