Brynn Metheny is the undisputed master of mashing up cats and sharks into delightful creatures. Her original series was so popular, she created a sequel this year.
She says:
In 2013, I scribbled a terrible little creature into my sketchbook: The Shark Cat. I illustrated a series of Shark Cats for a 2014 calendar and they became a bit of an internet sensation. They've been featured on reddit, Tor.com, io9 and other culture/art websites. This year I decided to revisit the concept with a second series. This series is for the shark lover, with more obscure and rare species.
Bonus video: a shark cat in the wild hunting a duck: