The Onceler is selling Thneeds to people and greeting them. When it's your turn to buy one, you notice him just smiling and giving you a Thneed. You notice a hearing aid on his ear and he starts signing: "Hi! Would you want a Thneed? It's really soft!" He signs without talking and fingerspells "Thneed". Luckily, you know sign since you're a CODA (Child of Deaf Adult), so you sign back to him.

(Nobody made a deaf onceler au and I'm so mad about it. So I decide to make one myself!!! Enjoy)