Mayapep

Mayapep is a sea dragon with a long body as fluid as the water it inhabits. It has dark blue, green, and purple scales that camouflage into the waves and have a surprising blubber-like quality. It has 6, fibrous fins, 3 on either side, that fan out and are the color of dark seaweed. It has round, glassy eyes and small, bioluminescent lights on its sides spanning from head to tail, glowing a soft blue-green. In the summer months, it's dark scales become more translucent and lighten, and the tips of its elegant fins turn a seafoam green.
It lives in the oceans around the waters of Seshat El Medin, in the depths where the sun barely reaches. Except for summer, where it stays in shallower waters until it gets cold again. Because of its pattern of only surfacing in warmer months, it is only ever sighted in the summer. Therefore, the flow of tourists that enter Seshat turn into hordes during the summer partly on account of Mayapep. Seshat even holds questionable boat rides claiming to allow people to get a close up view of the dragon, after they sign an extremely long waiver and liability form. Its main source of food are the fish that Seshat fishers catch, causing an unspoken competition between the two. However, the fishers would never mess with the dragon, as it can spit a stream of water with enough force to shoot right through the hull of a wooden ship. Furthermore, it moves through the water as silently as an assassin despite its mass and length, preferring to keep a low profile until it needs to strike.
Using the element of surprise is quite easy for this creature not just because of its silence. It also has the ability to become invisible due to the properties of its scales. The only semblance of a hint that the creature is there are the ripples that radiate from its body. Unfortunately, these scales are, therefore, highly coveted by humans and other intelligent forms, to use as armor to fool the opponent in battle, fashion, or maybe just as a trophy for reputation. Mayapep is an endangered species due to the hunting of them for their scales.