Direct & Dominate (D&D)'s YouTube channel shows many videos that makes fun of Command and Conquer (C&C) with Pixar's Cars -- "... a parody fan animated series taking place in an alternate reality of the Command & Conquer universe."

Whitney Avalon's YouTube channel shows many rap/hip hop music video parodies based on (movie/f(ilm/lick))s including bloopers, karaokes, etc.

It's like Epic Rap Battle.

YouTube video channel shows several short music videos of "I take your favorite songs and ruin them forever."

http://www.youtube.com/c/AnythingbutEnterprise/

"Welcome Everyone! This Channel is dedicated to my friend, whose dislike for this main theme song is so great, that he once said to me 'You could put in ANY theme song in here and it would still be better than 'Enterprise'. So here you go, friend! Enjoy these themes from other shows over this beautifully designed main title of Star Trek: Enterprise. (Seriously, it's my favorite opening visually). If there's a particular theme you'd like to hear, let me know. I'd love to see how it works ..."

http://www.youtube.com/user/9freakydarling9/

"Medieval $hitposting, also fondly known as Bardcore, for the discerning clergyman, noble, or muck-gathering peasant."

There are currently only four music videos. Hopefully, it will have many more in the future.

It's a Southern Thing's YouTube channel shows many video parodies showing "Southern comedy, culture, food, and more, y'all!"

OwlKitty's YouTube channel:

"Lizzy (stage name: OwlKitty) is a two year-old cat living in Portland, Oregon. She stars in all your favorite movies and tv shows and gets lots of treats and cuddles in return. Offscreen, Lizzy loves her laser pointer, her adoptive mother (a 10 year-old tabby) and the taste of cream cheese. She’s never caught a bird.

So far, OwlKitty has made appearances in such classics as Star Wars, Harry Potter, Jurassic Park, How to Train your Dragon, The Shining, Titanic, 50 Shades of Gray and Risky Business. You can also find her in Game of Thrones, The Lion king and Stranger Things."

Anwar Jibawi's two years old YouTube channel has many funny short sk(it/etch) videos. A new one gets added once a week.

http://www.youtube.com/playlist?list=PLr7X3psVUb5BgG2GMqIfHDkTzzxOlwyUf

So many. Pick your favorite and submit.

Peter Hollens' YouTube channel has many music videos using only his voice and mouth based on popular tunes from (movie/f(ilm/lick))s, video games, etc. Also, he sometimes uses special guests and costumes.

Ctrl Shift Face's YouTube channel is "Windows to parallel universes. I'm creating entertaining deepfake videos. Do not believe everything that you see on the internet ok?"

LOL ComediHa!'s YouTube channel shows many very short and a few long silly video sk(it/etche)s -- "Lol :-) is a real funnny tv show of a great quality. The skits are funnier one than the other, the settings are gorgeous and the actors are extraordinary. This compilation of funny videos will make you laugh so hard...

WTMRecut's YouTube channel has several parodied videos from movie/f(lick/ilm)s and tel(evision/lly)/TV s(erie/how)s. They can be amusing too.

For an example with its recent video from Reddit with this amusing a 1.25 minutes YouTube video showing "Ripley Power Loader FAIL | 'Aliens' Recut -- Ripley offers her Power Loader skills to Hicks and Apone...but she may need to go back to training..." -- I submitted into https://videosift.com/video/Ripley-Power-Loader-FAIL-Aliens-Recut

Nick Murray Willis's YouTube channel has many short funny cartoons on "ANIMATED - AUDIO Mash Ups! Giving sound from sports, movies and TV a new life."

http://www.youtube.com/user/SingingPup24/

"We are Disney•Pixar fanatics. We're especially enthusiastic about the Toy Story franchise. We have been working on a homemade version/remake of Disney•Pixar's Toy Story 3 for several years now. You will see "Toy Story 3 In Real Life" updates here."

There are multiple (currently six (seasons)) playlists showing "The best Movie and TV mashups on the internet Funny Or Die". Here is its (1/fir)st season.

Level UP's YouTube channel has a bunch of short funny videos related to video game consoles' games.

http://www.youtube.com/channel/UCchBatdUMZoMfJ3rIzgV84g has many hilarious videos from "... a bunch of nerds who play games and makes comedy sketches about games." like its Epic NPC Man.

I missed a lot too! Better late than never.

Lauris Beinerts' YouTube channel shows "Funny short comedy films / sketches / skits & any other videos / movies..." There are currently only nine/9, and hasn't posted any new videos for a year.