Which of these words first appeared in a Dr. Seuss book?

The origins of the word “nerd” are debated, but etymologists point to a 1950 book by Dr. Seuss as the first appearance of the epithet in print. In “If I Ran the Zoo,” a little boy named Gerald McGrew is dissatisfied with his local zoo and makes a number of inspired recommendations for improving the place. One of these is: "And then just to show them, I'll sail to Ka-Troo / And bring back an It-Kutch, a Preep, and a Proo, A Nerkle, a Nerd, and Seersucker, too!"

In the book is an accompanying image of a nerd that depicts a squat, humanoid, yellow creature with unkempt white hair, a red brow, and a displeased expression. He looks more like a great-uncle with indigestion than our modern image of a nerd, with a pocket protector, but he may be the earliest iteration of the species.