Hello again!
When I played Sonic R as a kid, it was so exciting to encounter the few new characters that hadn't appeared in the previous games in the series. Specifically, Metal Knuckles and the Tails Doll.
The Tails Doll has gained serious notoriety in the Sonic community as being one of the creepiest creations in the franchise. Most of Dr. Robotnik's inventions are metal and noisy, but Tails Doll just floats silently, almost aimlessly, with a dead expression. It was such a cool thing to include.
So, I have to ask, do you know who was responsible for its creation? Thank you!
My guess is that a robot design didn't suit Tails, so they decided on a doll instead. I always imagined there was a levitating robot inside the doll and its antenna is sticking out the top.