He looks a lot like the Purple Doctorfish and Dr. Gill Gilliam, except Dr. Gill is light olive-green and wears a light blue uniform instead of a white one, and a dark gray and light blue head mirror.
Role in book
He is first mentioned when SpongeBob tells Patrick that he better come with SpongeBob to see his Dentist, Dr. Gill.
When SpongeBob and Patrick get to Dr. Gill's Office, SpongeBob mentions Dr. Gill by mentioning the office.
Soon, SpongeBob mentions Dr. Gill by mentioning that Debbie is Gill's hygienist.
Dr. Gill then says, "Do I hear SpongeBob?" SpongeBob greets him and tells Patrick that Dr. Gill makes sure that one has cavities.
Debbie and Dr. Gill enter the waiting room. SpongeBob, Debbie, and Gill take hands and dance in a circle, singing, "I brush and floss my teeth each day to ward away that tooth decay!"
Later, after Debbie does her job, Dr. Gill checks SpongeBob's teeth. He says that they are healthy and that they will not know for sure until they check the x-rays. He then says that SpongeBob is a model patient. SpongeBob thanks Gill and tells him that Patrick has never been to the dentist before.
When it is Patrick's turn, Debbie and Dr. Gill look at Patrick's mouth. Gill tells his receptionist to cancel his appointments for the rest of the day because it will take awhile.
After cleaning Patrick's teeth, Dr. Gill finds out that the light box that they use to view the X-rays needs a new light bulb. He then tells SpongeBob and Patrick to go home and that he will call them tomorrow for the results as it will be fixed by then.
The next morning, Patrick mentions Dr. Gill when he mentions Dr. Gill's receptionist.
At SpongeBob's follow-up appointment, Dr. Gill greets SpongeBob and Patrick. He then looks at SpongeBob's x-rays. He starts to say something, but then realizes that the x-rays are not SpongeBob's and that his receptionist must have mixed SpongeBob and Patrick's x-rays up.
When SpongeBob gets up out of the chair, he, Debbie, Patrick, and Dr. Gill link arms and start dancing merrily.
Debbie mentions Dr. Gill when Patrick is in the chair to get his cavities fixed.
After Patrick gets his teeth filled, Dr. Gill tells him that he needs to floss his teeth every night and to brush them twice a day for at least two minutes each time. He also tells Patrick to come back in six months and that he can have a toothbrush from his drawer.