Golden Tektite

The golden tektite is a monster which looks like a normal tektite, but the golden tektite is much tougher and is also gold-colored. It will only appear as the result of a Kinstone Fusion. If Link defeats the beast, then a treasure chest will appear on the map. This creature only appears in The Minish Cap.

Quote from The Legend of Zelda: The Minish Cap Golden Tektite figurine: "Appears in... Well, we're not sure! The legendary Golden Tektite. Its basic attack is the same, but it has much more power."