From the Super Mario Wiki
“My Flab boys are gonna free me from this place!”
In The Super Mario Bros. Super Show! episode "Bad Rap", King James had been taken hostage in his own castle by Rappin' Koopa. Rappin' Koopa had placed King James onto a giant turntable, where he would inevitably get stabbed with the giant record needle that went along with it. However, King James was confident that the Flab Boys would rescue him and soon learned that Rappin' Koopa had spotted them, along with Mario, Luigi, Princess Toadstool and Toad as they approached the castle.
King James soon met up with Princess Toadstool, who had unfortunately been captured by Rappin' Koopa. Rappin' Koopa then turned on the record player, and left the King and Princess alone as the needle slowly lowered towards them. Thankfully, Toad managed to sneak in and turn off the record player, saving them.
After meeting up with the Mario Bros., King James declared that the only way to stop Rappin' Koopa was to shut off his power by pulling the Royal Plug of Rap Land's power supply. Mario eventually succeeded in pulling the enormous plug.
To counter Rappin' Koopa's attack, King James assisted Princess Toadstool in blowing up several Albatosses with exploding records (see Stereo Gun). Due to the Albatosses disappearance, the others were able to take out Rappin' Koopa and his Koopa Troopas, freeing Rap Land from their reign.
He bears a surprising has a resemblance to King James I of England.