Arturo Huerta
From Blaseball Wiki
Arturo Huerta is a pitcher for the Seattle Garages[1] and a vibraphone player for the Seattle Garages Rainy Day Attitudes. Nothing else is known about them.
Theodore Duende once famously said "there are many things we don't know about this world, and one of them is Arturo Huerta."
If you were to look up the word enigma in the dictionary, you would not find a picture of Huerta, as no known visual depiction of them exists. People who have seen them cannot describe their appearance even moments afterwords. Many fan artists have spent hours working on drawings of Huerta only to eventually realize their pages were blank the whole time.
