I've almost always had a general theme of naming all my fish after characters from something or another. Though I always kinda had a tendency to do so because I'm just a huge nerd, I started naming my bettas exclusively after characters when I worked at a local pet store so I wouldn't just bring home ALLLL the bettas(though I brought home quite a few anyway...
). It was kind of a rule I set for myself, I had to find a character and name that fit the betta before I could bring it home.
Now its just kind of progressed into a habit of how I look for names for my bettas. Of my current boys, I have....
Nine-A dragon character from a rather obscure web comic I'm a big fan of.
Mephisto(Mefishto)Pheles-Though a demon from German folklore, hes primarily named after the character from the anime Blue Exorcist, mostly due to his coloration.
Steve Rogers and Bruce Banner-The Avengers, obviously. I was pretty into them when I picked these two up last year for my birthday, I had a Tony Stark as well but he was a sympathy purchase from Petco who unfortunately didn't last the night.
Legolas-I'm sure most can guess this is from LoTR
Lucifer(Lucifish)-Named after the Fallen Angel, obviously, and partly inspired by the series Supernatural because I picked him up on the 21st of December last year when the world was supposed to end. xD
Gwaine-Sir Gwaine of Camelot, Knight of the Round Table....and my favorite character from the BBC series Merlin. xD
Nezumi-One of the main characters in the Anime/Manga series No. 6.
Tom Lucifer Rory Watson Pendragon von Jefferson-This is what happens when I let my friends name my fish.
We call him the Fandom fish, hes named after six different characters in six different series, though we usually just refer to him as Tom Lucifer.
My goodness I have a lot of fish....you don't really think about it until you start listing them out I guess.