Oh Brother - S1.E14

Rockna has always wanted a little brother and she gets her wish when the knights find a little centaur in the earth realm. Eccentro hears that a centaur king called the King Of 100 Battles has lost a great treasure, so he thinks its a monster item. Mondo becomes ticked off because Rockna is treating the centaur as a little brother. Eccentro attacks the knight with the Nine-Headed Swamp Dragon, but the knights are able to merge with the King Of 100 Battles to defeat the dragon. When the knights ask the king about his lost treasure, he reveals that the treasure was his son, the centaur Mondo and Rockna found.