What are the creatures that give the most and the least experience when killed?

Question

Taking only regular creatures and not summons or bosses in consideration, what is the creature that gives the most experience and the least experience in the game when killed?

Answer 1

Currently, the non-boss creature that yields most experience is the Brain Squid, which yields 21000 experience points. The creatures that yields less experience are Penguins and the "fake" Phantasms which yield 1 experience point.