King Sammer (a.k.a. King Sammer V) is the leader of the Sammer Guys that appeared in The Flip Flop Show. To reach him, Bleu must defeat all 100 Sammer Guys throughout his land, Sammer's Kingdom. In Chapter 6-1, Bleu and his teammates arrive at his kingdom and meet with the king. He was in possession of the Pure Heart of this Chapter and agrees only to give it to the adventurers if they defeat his 100 Sammer Guys. Bleu and Co. do not defeat the Sammer Guys in time because of Lucy, who slows them down with a fight, and Sammer's Kingdom is destroyed along with the king himself. At the end of the show, Sammer's Kingdom is brought back to existence, along with its inhabitants. When the Bleu beats all 100 of his Sammer Guys, he gives Bleu seven rare Catch Cards.
Official art of King Sammer.
According to Garson of the Flipside bar, The Underwhere, the younger sister of Merlumina was sent to Sammer's Kingdom to deliver the purple Pure Heart to King Sammer I, but fell in love with him and stayed behind. The two eventually got married and ended having 100 children together. If this story is true, this means that King Sammer V is a descendant of the Ancients. The 100 vassals may also be a reference to their 100 children.