That Frog Kurtis (aka T.F. Kurtis) is the antagonist of the pilot of the Black Dynamite animated series, Trouble on Puppet Street. He's voiced by J.B. Smoove.
When Black Dynamite was a child, T.F. Kurtis was the star of his favorite show. After his father left, Kurtis' teachings and antics made him into a surrogate parental figure for young Black Dynamite.
Unfortunately, Kurtis had grown corrupt over the years, and was teaching bad lessons for children, as well as becoming something of a gang leader over the other puppets.
B.D. and his crew infiltrated T.F. Kurtis' operation and killed them. Little did Black Dynamite know, though, that Kurtis had many children, including one that would harbor an intense grudge against Black Dynamite, That Bastard Kurtis.
He's a parody of Kermit the Frog, leader of the Muppets.