Merman is a Mer Creature. He was Link's seventh creature.
His card, along with the Move Card Technique Boost, winded up in a lake in Lesotho. He was activated when a fish knocked open his Capsule. He battled Penguin and lost. His capture removed Penguin from the team. He was later revealed to be a 2 on the Power Scale. Sixteen episodes later, he battled in a battle royale, but was easily defeated. Two episodes later, he battled in another battle royale, but was defeated easily. Six episodes later, he battled in a battle royale, but lost just as easily. The next episode, he battled a Future Fungus, but lost. The next episode, he was removed from the team by Stomper's capture.
The Technique Boost Move Card was in his Card Capsule, and was activated along with him.
He has never won a battle.