Any organism that you can think of, microscopic or macroscopic, and yes including those somewhere in-between that we’re not sure how to classify as alive or not (i.e. viruses).
Which would you most like to conduct an interview with, and what might some of your questions be?
My dog. What the heck goes through her tiny dumb, dumb brain? I mean, I’m sure it would be about 90% “feed me! pet my belly! give me cookies!” But that other 10% might explain a lot.