Jefftastic's Documentation

In a similar vein to Greenio's Lost Tapes, Youtuber jefftastic has created a series of Super Mario 64 videos based around documenting and demonstrating phenomena in video form. Unlike Greenio's tapes which are presented as found footage, jefftastic's videos are more of a present-day documentation. All of jefftastic's videos on the matter have been cataloged in a playlist called Super Mario 64 documentation.

WEC Sighting (and other anomalies)
The first video in the series features jefftastic playing through Bob-omb Battlefield. Here, an instance of Dynamic Level Rearrangement is caught on video. Most notably, the sky and fog have gotten a distinct orange tint that is reminiscent of a sunset. Secondly, the star that was once behind the gate the Chain Chomp guards has been replaced with a row of five coins. The sign that is nearby also has its text changed to go on for a few extra blank boxes, before eeriely saying "Your fear is justified."

The highlight of the video is the appearance of the White-eyed Chomp. As commonly known and as told in the description of the video, the White-eyed Chomp signifies future anomalies for jefftastic to encounter.

Bowser Room Discovery
This video starts with jefftastic booting up the game, when his save file loads, he looks at the background of the Castle Grounds, which looks like the background of Bob-omb Battefield from last video. He then goes to the room with the Jolly Roger Bay's painting and goes to the Secret Aquarium, but instead he gets teleported to the Bowser Room, where he has to collect 8 red coins to get the star, he collects all coins and gets the star.

Flying Fortress (Whomp's Fortress beta?)
In this video, jefftastic opens the door to the room of Whomp's Fortress' painting and jumps to it, in the star select screen, the stage is named Flying Fortress instead of Whomp's Fortress. When entering the stage, there's another instance of Dynamic Level Rearrangement, the song is the SMB1 overworld theme, like in Bob-omb Battlefield. Secondly, the layout is different, even with the fortress containing a sub-area inside. When entering the fortress, the Whomp King is inside and you have to defeat him to get a star, when he gets the star and goes back to the castle, the game crashes and there's a jump cut. He gets another star and then there's a message saying the castle has changed.

Castle Garden (and Dark Room)
In this video, jefftastic goes to the Castle Courtyard, but it changed to the Castle Garden, he then enters a door to the Dark Room, where there's a door and a toad that tells Mario that they're all trapped in the castle walls and asks Mario for help, he enters the door, but the video ends before we get to see what's inside.

Delicious Cake
In this video, jefftastic is in the Castle Gardens, he then goes to the Dark Room, but the Toad in there is replaced with a big box he destroys and then goes to the door to a room where there's a table with a cake, as Mario jumps on the cake he gets teleported to the Delicious Cake level, there's a message of Princess Peach to Mario, he then gets the star and the screen goes black. Someone comunicates with jefftastic (presumably Stanley) and then the game goes back to the title screen.

Mario Update
Unlike the other videos, this video is recorded off screen. Jefftastic narrates the video, explaining how his copy of Super Mario 64 is now refusing to boot up on his Nintendo 64. He shows this, trying to power on his Nintendo 64 with Super Mario 64 inserted, to no avail. He then tries with another game, where it does work. Jefftastic explains that he'll be getting a new copy of Super Mario 64 and continuing to document any anomalies that he finds.

Trivia

 * jefftastic's first video has the first ever instance of Dynamic Level Rearrangement caught on video.