“Fizzician” (fizz + physician) is a jocular portmanteau term. A popular riddle is:
   
Q: What kind of doctor is Dr Pepper?
A: He’s a fizzician.
   
“Dr Pepper’s a fizzician” was posted on Twitter by Neil on April 14, 2013. “DR. PEPPER IS A FIZZICIAN” was posted on Twitter by Sal F on January 15, 2015. “Dr. Pepper is a FIZZician” was posted on Twitter by mahtwog on September 8, 2018.
   
“What kind of doctor is Dr. Pepper? A fizziscian” was posted on Reddit—Dadjokes on December 14 ,2019.
   
     
Wikipedia: Dr Pepper
Dr Pepper is a carbonated soft drink. It was created in the 1880s by pharmacist Charles Alderton in Waco, Texas, and first served around 1885. Dr Pepper was first nationally marketed in the United States in 1904, and is now also sold in Europe, Asia, North and South America. In Australia, New Zealand and South Africa, Dr Pepper is sold as an imported good. Variants include Diet Dr Pepper and, beginning in the 2000s, a line of additional flavors.
       
Twitter
Neil
@_Enanem_
Dr Pepper’s a fizzician.
6:08 AM · Apr 14, 2013·TweetList Pro
   
Twitter
Greg
@GrowlyGrego
MEDICAL FACT: Dr. Pepper developed 19 of his 23 flavors while he was still a lowly fizzician’s assistant in a dialysis clinic.
11:00 AM · Sep 18, 2013·Twitter Web Client
   
Twitter
In THA Burbs
@InThaBurbs
Dr. Pepper is a Fizzician, his brother Mr. Pibb is a disappointment to the family after dropping out of med school.
6:21 PM · Apr 4, 2014·Twitter for iPhone
   
Twitter
Sal F
@ThenSalmanSaid
DR. PEPPER IS A FIZZICIAN
2:29 PM · Jan 15, 2015·Twitter for iPhone
   
Twitter
Neil
@_Enanem_
Dr Pepper’s a fizzician.
6:06 AM · Apr 4, 2018·Twitter for iPhone
   
Twitter
mahtwog
@gtamr_
Dr. Pepper is a FIZZician
3:02 PM · Sep 8, 2018·Twitter for iPhone
 
Reddit—Dadjokes   
Posted by u/gunsmith123 December 14, 2019
What kind of doctor is Dr. Pepper?
A fizziscian
       
Twitter
𝓜𝓪𝓻𝔂 𝓕𝓸𝓻𝓭𝓮
@ImpossiblyBossy
What kind of doctor is Dr. Pepper?
A fizzician! 😂
5:18 PM · Dec 14, 2019·Twitter for iPhone
 
Twitter
Dad Jokes
@Dadsaysjokes
What kind of doctor is Dr. Pepper?
A fizzician.
8:17 AM · Dec 15, 2019·Twitter for iPhone
 
Reddit—Jokes
Posted by u/gwiisoon December 18, 2019
What kind of doctor is Dr. Pepper?
A fizzician.
 
Reddit—Jokes
Posted by u/M_Class01 December 29, 2019
What kind of doctor is “Dr Pepper”?
No kind at all. The period was dropped on the 50s as part of a redesign. This forever changed the respectable “Dr. Pepper” into the dimwitted “Dhhhhurrrr (“Dr”) Pepper”.
That’s right. The answer is not ANOTHER repost of “a fizzician”.
     
9 April 2020, Daily Star (London, UK), pg. 30:
What kind of doctor is a Dr Pepper. A fizzician. Keeley R .
 
Reddit—ApparentJokes
Posted by u/DokCyber October 21, 2021
What kind of doctor is Dr. Pepper? A fizzician.
What kind of doctor is Dr. Pepper? A fizzician.
 
Reddit—Cleanjokes 
Posted by u/chacham2 February 20, 2022
Hey, just finished my list
(...)
What kind of Dr. is Dr. Pepper? He’s a Fizzician.
 
Twitter
Dad Jokes
@Dadsaysjokes
What kind of doctor is Dr. Pepper.
A FIZZician.
3:27 PM · Mar 24, 2022·Twitter for iPhone