A marine biologist became very attached to the mammals at the institute where he did his research. The death of one of the dolphins threw him into such a funk that he vowed to never let it happen again. So he developed a serum - from a certain tropical bird, as it happened – that would heal almost anything that ocean going mammals fell prey to. The institute's orca was among the longest-lived cetaceans in the world.
The serum eventually ran out and, unfortunately, it's extraction had required the destruction of the institute's only specimen of the bird. The scientist went to the city's zoo one night and sneaked into the aviary where he located another specimen. On this very night the zoo's rather elderly lion, long due for replacement but for the city's longstanding budgetary woes, escaped from it's pen. Exhausted after a short chase pursued by the zookeeper with the aid of the local police, he went to sleep across the footpath leading from the bird exhibit.
Just then the biologist came nervously racing towards the fences intent on escaping with the captured bird. He leaped over the dozing big cat right into the arms of the oncoming police who immediately placed him under arrest. They charged him with crossing a staid lion with a mynah for immortal porpoises.