I need to keep track of these since Blue has at some time got more. They are only imaginary plushies, but I wouldn't mind making physical ones too.
Hunter
Hunter is an Optimus plushie. His name comes from his first name being Orion, and the Greek Orion was a hunter.
Goo
Goo is a Rodimus plushie. The line of logic goes: Rodimus - Roddy - Rod - Stick - Sticky - Goo.
Sting
Blue channelled one of my old plotbunnies here, one where Tracks was a stalker. As a result Blue's Tracks plushie is named this because the old Police song "Every Step You Take" is very damn stalkerish and the singer, Sting, was the lead singer of the Police.
Bun-Bun
Bun-Bun's name is simple, Cyclonus has those bunny-ear horns.
George
This plushie, a Sunstorm one, is actually the first. Blue's reaction was to repeat a line from an old cartoon "I'll love him and hug him and pet him and call him 'George'".
Hecate
Blue may have got a bit mixed up about Greek myth here because he was thinking about three-faced goddesses and the only name he could think of that may be so was Hecate. Three-faced because this plushie is Animated Blitzwing. ETA: Turns out Blue guessed well on the name - Hecate was triune goddess.
Howl
When your nickname is "Screamer", "Howl" comes close, doesn't it?
Squid
Movieverse Soundwave has lots of tentacles so he immediately got named after something else with tentacles.
Cthulu
Blue was probably looking over my shoulder when I recently reread TV Tropes, where they referred to Unicron as a "Cosmic Horror". Blue got this plush from the resident Unicron of the household, as he makes plushies for his minicons.
Dorito
This is a slight shortening of Drift's Japanese trasliteration - Dorifuto. Combine that with memories of the Wiki's caption about the Allspark fragment in the '07 movie (Autobot Dorito of Leadership) and now Blue has a Drift plushie - complete with bendy swords - named after a corn chip brand.
Flash
He's an Ultra Magnus plushie, named after a TFA fic name for Magnus - Ultraflash. Thing is, Flash is a G1 Magnus plushie. Not that Blue cares about continuity mix-ups in his plushie names.
Magnificent Bastard
Movieverse Sentinel Prime plushie. After finding out his actions in DotM, Sentinel Prime got dubbed a "Magnificent Bastard" and as a result Blue now also has a plushie of Sent, wearing that name.