David Winkle is a pedophile, sex offender, and a serial killer who appeared as the main antagonist in the Bowser Junior's 1st Grade! series. He first appeared in Part 2 of the First Grade series, where he replaced Mr. Wilfred as the teacher after Joseph accidentally broke Mr. Wilfred's hip while he tried to take Joseph's phone.
In his debut appearance, Mr. Winkle revealed that he is a sex offender and demonstrated perverted characteristics as well. He was arrested by Officer Goodman in Part 3 of Bowser Junior's First Grade after taking "school photos" of the students on his iPhone.
David Winkle first appeared in Bowser Junior's 1st Grade! Part 2, as Bowser Junior's first grade teacher. He reveals to the class that he is a sex offender, and demonstrates abnormal, inappropriate, creepy and perverted behaviors. He also appeared in Bowser Junior's 1st Grade! Part 3, where he was arrested while taking photos of the students. He was replaced by Jackie Chu as Bowser Junior's 1st Grade Teacher in subsequent episodes of the series.
In Bowser Junior's 1st Grade! Part 5, he returns to the school disguised as Jackie Chu. He fools everyone (except Cody and Jackie Twu). It is unknown how most people were oblivious to this even though he wrote "Mr. W" on the board, kept saying things "were hot", exhibiting his usual peverted behaviour and saying he was Jackie Chan instead of Jackie Chu. When the school burnt down from Junior lighting the paper on fire, he was arrested yet again, this time by Officer Brooklyn T. Guy.
While he did not appear in this video, he was mentioned as the murderer in The Gun! where he murders 15 kids at a playground, going from being a child predator to a child murderer with no explanation. He was arrested again after the police found his gun under the slide.
I'll take that! Ha! No gum in class kids. (First lines)
"That's hot." (Catchphrase/Repeated line)
"DUCK, do do do do, DUCK, do do do do do, GOOSE! you're a goose!."
"I am living the American dream right now"
"That is NOT HOT"
"Sorry kids, I'm going away for a while!" (Mr. Winkle's comeuppance)
"Me Chinese. Me make joke. Me go pee-pee in your Coke." (Impersonating Jackie Chu)
"Shut up you hot little shit, you're blowing my cover!" (Whispering to Jackie Twu)
"G is for...uh...God-damn, what is that?"
"I had that American laser eye surgery."
"Class, class, there's a fire in the classroom! Get in the corner and panic, now!"
In Part 2 of Bowser Junior's 1st Grade, Mr. Winkle says his name is David, but later claims it is Daniel in Part 3.
It is also stated in an early appearance that he lived in Kentucky but in his later appearances he reveals that he was born in Detroit, but it's possible he may have moved to Kentucky at some point or might just be lying.
It's currently unknown how Mr. Winkle got out of jail, as he broke into Bowser Junior's apartment.