What is tough skin on pinky finger the size of a red pea?

Did it appear out of the blue, or did it grow over (a certain period of) time?
Did you hurt your pinky before and is this the result?

Sounds like a blister, I got one on my pinky from touching a pan right out of the 400* F.

Could be a lot of things. What have you done with your hands over the past few days? Could it be a small thorn or splinter that got a bit infected. It could be a spider bite. It could be a cyst or even a pimple or an in-grown hair. If it bothers you and you can’t figure it out, go to a doctor. If you just want to get rid of it, try applying hot compresses and use tribiotic ointment.

That sounds kind of like a wart.

Look up warts online and see if it looks like your bump.