My Charmander's nicknamed Elliott for Elliott Smith and Elliot the Dragon.
My Pichu's nicknamed Pikabu to keep the legacy of Pikabu's going in my Pokemon games. I always have a Pikachu named Pikabu because of the sound similarities.
I nicknamed my Bidoof Yoshi in honor of my late great lazy dog of the same name.
I nicknamed Geodude Gaea based off of the old supercontinent of Earth due to his earthy rock feel.
I nicknamed Paras MagicShamn in reference to psychedelic mushrooms.
I nicknamed Cyndaquil Ra in honor of the Egyptian God.
And I nicknamed Shinx Blimba because of it being the lion cub and Simba from The Lion King was a lion cub, Shinx is blue, so there ya go... Blimba.
That's what I got for now of Pokemon nicknames haha