Otter Learning To Swim

Gavin Maxwell's book Ring of Bright Water tells the tale of how he brought a Smooth-coated Otter (Lutrogale perspicillata) back from Iraq and raised it in 'Camusfearna' (Sandaig), on the west coast of Scotland.
The animated Nickelodeon TV show The Penguins of Madagascar features an otter character named Marlene, voiced by Nicole Sullivan.
In the book and movie Harry Potter and the Order of the Phoenix, Hermione Granger's Patronus takes the shape of an otter.
Rigby's counterpart Doug Shlibowski from Regular Show episode "Temp Check" is an evil otter that tries to replace him as Mordecai's friend.