On Sesame Street, who “turned” The Count? Or, if he is the original vampire, has he ever turned anyone into one of his thralls? Any scenes which might be taken as evidence that he has done so?
The Count was interviewed by WIRED in a video released February 22, 2017 (WIRED (2017-02-22), The Cast of 'Sesame Street' Answer the Web's Most Searched Questions | WIRED, retrieved 2017-03-01). In the interview, he says he will be 6,523,728 years old "next October.
According to the Noddist book of Enoch, this places him in Enoch (the first city) as a companion of at least the antedeluvians. His counting obsession suggests a lineage from Malkav, but in the credits of Sesame Street movie Follow That Bird the Count appeared on-screen during the closing credits where he proceeded to read and count the credits. He also says "Hi, Mom" when a credit appears for Joan Ganz Cooney, creator of Sesame Street.
This suggests that Cooney is his sire, making his lineage Caine - Enoch - Malkav - Cooney - Count. A powerful 5th Generation - thus explaining his potency and occult powers. He has been observed with his 'children' - the bats - Sasha, Misha, Grisha and Tatiana, but it is unclear if they are his childer or his pets.
He has made mention of Uncles, brothers, grandparents and a mother and the presence of Countess Von Backwards, Countess Dahling Von Dahling and 'The Countess' demonstrate others with the same clan insanity suggesting either a shared sire (Cooney?) or offspring.
In terms of the Count turning anyone, there is this video evidence of a vampire attack on a hapless actor, which occurred after the newly sired vampire's interaction with The Count in a Great Muppet Caper.