At first, he is seen as a pink figure in the video, but after he gets electrocuted, he becomes a skeleton.
His name was revealed by his plush's product name.
His gender was revealed by his plush information.
Dummbkopf was named after his great grandfather, who enjoyed bomb disposal as a hobby. His name is German and roughly translated means someone who puts a fork in a toaster without pulling the plug out first. He is distantly related to Hapless, who also likes to prod dangerous things.
In the video
Dummkopf is seen holding a toaster with a fork right in front of him, and then lifts it up like in the picture above and gets electrocuted. After so, his burnt flesh falls to the ground, revealing his skeleton. He is a Second Dancer, just like Lax, Doofus and Mishap.
The player must carefully remove a piece of toast with a fork without touching the sides. If you fail, Dummkopf will get electrocuted. If you win, he will get his toast.
As part of the second update, he has a new game. This game requires you to prevent appliances from falling into the sink where he is washing dishes. If any of the appliances touch the sink, Dummkopf becomes a skeleton again, resulting in failure. If you win, he gets a piece of toast and eats it.