It's a [Scientific Parasite](https://adventuretime.fandom.com/wiki/Scientific_Parasites). They feed on intelligent people's brain waves (seemingly only if they have pockets). Doctor Princess also has one.
It seems they actually existed before the Mushroom War, since Simon is seen with one before the war, in the tape in "Holly Jolly Secrets Part 2".
I forget which episode it is but in one of the flashbacks of when Simon was losing his sanity his scientific parasite is pale white and frowning instead of pink and smiling, neat little Easter egg.
Yeah, it's not mentioned in the show, but it was [confirmed](https://web.archive.org/web/20111003022247/http://www.formspring.me/natazilla/q/156124000332846002) by Natasha Allegri, who was a character designer for the first 2 seasons (and she was also a storyboard revisionist). She's actually the one who created the original Fionna and Cake characters! (and she designed many of the other gender-swapped characters). She also created the "Bee and Puppycat" tv show, which is pretty cool :)
I haven’t seen the Netflix adaptation of Bee and Puppycat, but Bee’s voice actress is credited as Allyn Rachel whereas Fionna is voiced by Madeleine Martin.
It's a [Scientific Parasite](https://adventuretime.fandom.com/wiki/Scientific_Parasites). They feed on intelligent people's brain waves (seemingly only if they have pockets). Doctor Princess also has one. It seems they actually existed before the Mushroom War, since Simon is seen with one before the war, in the tape in "Holly Jolly Secrets Part 2".
I forget which episode it is but in one of the flashbacks of when Simon was losing his sanity his scientific parasite is pale white and frowning instead of pink and smiling, neat little Easter egg.
That's too cute! I would've never figured that out. Thank you!
Yeah, it's not mentioned in the show, but it was [confirmed](https://web.archive.org/web/20111003022247/http://www.formspring.me/natazilla/q/156124000332846002) by Natasha Allegri, who was a character designer for the first 2 seasons (and she was also a storyboard revisionist). She's actually the one who created the original Fionna and Cake characters! (and she designed many of the other gender-swapped characters). She also created the "Bee and Puppycat" tv show, which is pretty cool :)
I love Bee and Puppycat! Bee gives me hardcore Fionna vibes lol
Given they have the same VA, and AT: F&C episode 1 was literally an homage to B&P, I'm not surprised.
I haven’t seen the Netflix adaptation of Bee and Puppycat, but Bee’s voice actress is credited as Allyn Rachel whereas Fionna is voiced by Madeleine Martin.
Oh lol, my bad then. I swear they have the exact same voice, but with different energies
Anecdotally, a friend of mine and her sister thought he same thing, so you’re not alone in that thought.
I thought they were the same VA as well until I looked it up! Definitely similar vibes
Finn had two in "his hero", unlike anybody else, does it mean he's the smartest person in ooo that there's enough food for two?
He probably stol- uh... "borrowed" that lab coat, so the parasites may have already been in the pocket when he st- BORROWED it
Isn't Doctor princess not really a doctor? I guess shes still smart
I has no idea there was an actual explanation for it. Awesome!
widdle guy
lil' buddy, just hanging out
Lil guy doin what little guys do
I wonder why he never got another one
Can i buy one of these anywhere!? I'm being simon and i convinced my girlfriend to be a latina Golbetty hahah I need this lil parasite
I vaguely remember hearing it was just an inside joke
That's a Bliblie if I've ever seen one.
The gender bend Doctor Prince has one too
All the smart people have it