A BBC documentary shows how dolphines drug themselves with puffer fishes

Despite their originality, no one could expect that dolphins use to take drugs in such a creative and conscious way, as revealed by a recent BBC documentary. In this series of two episodes, which has seen previous episodes dedicated to other mammals, the crew of technicians and cameramen of the English broadcasters used hidden cameras camouflaged as animals, such as tuna and turtles, to follow the mammalian natural behaviors without interfering with them. And so it was possible to document for the first time the usage of narcotics by dolphins, in this case Tursiops (Tursiops truncatus) along the coasts of East Africa.
In the shootings a small group of cetaceans use the puffer fish to "get high". In fact if the fishes are bothered, they blow up becoming spherical and often release a very powerful poison in small quantities, the tetraodontothoxin, which has a narcotic effect.
The dolphins pass the angry puffer fish to each others, holding it on the tail.
We can see that they do not want to eat it or even hurt it seriously, and the consequences of this treatment leave no doubt: the cetaceans remain stomach up, look at their reflections on the surface of the sea and move slowly, as if they were in trance.

I suggest you to watch the video, because it is very funny and interesting too.