The Potato Whisperer.
How odd that a company wouldn't want to admit, privately, that one of their products was sponsored. It's almost as if it wasn't and Mushbrain is just a liar.
Or how's this for a plot twist? He thinks that this is the case and in reality it's Medium T, Jack Jr and Charles that are sending him these things to stroke his ego and make him think he's a big important youtuber with loads of fans and connections.
It makes about as much sense as him LARPing as a cook.