Well, assuming that you have sleeves that can accommodate to begin with--the very smallest known Pokemon is still easily yhe size of a person's fist...
*give him a moment, this requires a bit more thought than sort the 'dex by size and filtering for the desired move*
Probably Salandit, really. It's a bit larger, about as long as your arm, but most of that is just long body and tail. So if you could teach it to lay flat, gripping your arm, it could probably manage.
Another possibility may be Inkay. They're smaller than Salandit, and if I recall quite good at squeezing into small spaces, but I'm not certain how well one would be able to hold on in the right position.
*see, you never know what you might learn if you ask!*
no subject
*give him a moment, this requires a bit more thought than sort the 'dex by size and filtering for the desired move*
Probably Salandit, really. It's a bit larger, about as long as your arm, but most of that is just long body and tail. So if you could teach it to lay flat, gripping your arm, it could probably manage.
Another possibility may be Inkay. They're smaller than Salandit, and if I recall quite good at squeezing into small spaces, but I'm not certain how well one would be able to hold on in the right position.
*see, you never know what you might learn if you ask!*