"Smeagol" is the name of a genus of sea slugs of the family of mollusks called Smeagolidae. They exist in New Zeeland and Australia. The first of the species was discovered in 1971 and in 1980 it was named Smeagol manneringi after you know who. F. M. Climo, who named the new order, family and species, wrote this in the New Zealand Journal of Zoology in 1980:
“The genus takes its name from the pallid, sometimes subterranean Tolkien character Smeagol (whose alternative name is Gollum), a pitiable humanoid who ultimately played a very important role in saving ‘Middle earth’ from evil forces. The slug described below is far more significant, phylogenetically, than its drab exterior indicates – hence the analogy.”
And if you think that that was the only biologic occurrence of Tolkien characters, you're wrong! Biologist Leigh Van Valen named 20 (!) fossil mammals he discovered after characters from Tolkien’s works. Among them are Bomburia, Mimatuta morgoth and Earendil, to name a few.
So there you have it, fellow biologists, a new reason to discover species: to name them after your favorite literary characters!