Dr. Trayaurus is a friend and companion to Dan on most of his mod reviews. He is a minecraft villager who conducts tests and gathers results on each mod while Dan reviews the mod in the testing chamber of theskinvideo. Edit
Dr. Trayaurus looks like a normal Librarian Villager, however there are situations in which he changes his appearance in accordance with the particular mod review or event.
Dr. Trayaurus seems to be quite the prankster as he has trolled Dan in many showcases. He also isn't the most honest of villagers as you can see in the "Coffee and Tea" mod when Trayaurus cheats by adding a secret ingredient!
Trayaurus first appeared in Dan's "Carboniferous" mod review as a explorer who betrays Dan but is given a second chance by Dan in the Atum mod review. Trayaurus mainly works in the lab, but has been employed at other companies as well. His first job other than the lab was at the Happle store (iPad mod version of the Apple store), but that Job ended tragically when Dan blew up the side of the store, killing all of the customers and putting Trayaurus out of a job. Trayaurus, unemployed, got a job in the McDonolald's dimension. During the "fruit" mod, he also stole Dan's lemonade that he needed to light a portal to the fruit dimension and started a lemonade stand.
He spends time with Dan, invents stuff and has secrets to rule the world...