Skrelp is a brown aquatic Pokémon that resembles a common sea dragon. It has a purple face and neck, red eyes rimmed with black, a tubular, upturned snout, a leaf-like pectoral fin on either side of its head, and a large, roundish lump on top of its head. A light blue, round growth is attached to the back of its head by a thin brown stem. Its back has a slight hunch with a blunt spike. On either side of its body is a rounded, light blue fin and it has a striated, purple belly. Its tail is composed of three leaf-like fins.
Skrelp is a poor swimmer, so it camouflages itself as seaweed to hide from enemies while storing power for evolution. It also uses this technique to hide from prey, which it sprays with liquid poison when approached. However, its main source of food is rotten seaweed. Skrelp is known to coexist well with Dhelmise.