Dr. Zimmer

Dr. Zimmer is a scientist that studies various subjects. He first appears in "Sue Ellen Moves In" in Arthur's imagination where Sue Ellen is a spy for Ngngafajhg. He appeared again in "Sue Ellen's Lost Diary" in Francine's imagination explaining Ogre-ism and why mean people should be kept separate from other kids. He has a German accent in "Sue Ellen's Lost Dairy," which references Albert Einstein, along with his uncombed white hair. Considering how he only appeared in imagination, he may not be real at all.