Check out this video on April Fools Math! The content is about Complex Numbers. Really funny. 🙂 Over a million views!
Also, check out this post on Math Jokes:
https://mathtuition88.com/2014/03/08/math-jokes/
Also, we have a series of Best Fake Proofs on Math Stackexchange:
What went wrong?
Amazing Endless Growing Chocolate! Can you spot the magic?
Math Jokes 4 Mathy Folks