The Physical Over-Achiever
The Discourse
The Wrecking Ball

Snap Crackle Pop (Culture)
The Screamer
Moves With Their Mouth
The Romeo
"That's great and all but... you're gorgeous. I'm in love with you."
I get it that it's a cold, cruel world and we're all just lonely people looking for a little attention, but an improv scene is not the place to look for love. This improviser is always falling head over heels in a comedic fashion for their scene partners, and you know what? Sometimes it sure is funny and sweet. :)
The Shocker

International Man of Mystery
"Yes."
"Why don't we go over there!"
"Sure."
"Wow! Look at that crocodile."
"That sure is a crocodile."
Who are they and what are they hiding, you wonder. Every scene feels like a painful interrogation, and leaves you feeling shaken (not stirred).
You
Of course, there are PLENTY more types of improvisers! I may do a sequel to this article, but for now, share other types of improvisers you know in the comments!