As of Level 38 Here’s a List of Current Available Premium Characters, still available, in TSTO:
Listed Alphabetically. Click on the Character’s Name For More
Arnie Pye
Barney
Bumblebee Man
Disco Stu
Dr. Nick
Drederick Tatum
Duffman
Hank Scorpio
Hans Moleman
Jasper
Kearney
Lugash
Prof. Frink
Rich Texan
Sherri and Terri
Sideshow Mel
Squeaky Voiced Teen