Loudred is a blue boxy-shaped bipedal Pokémon. It has a huge mouth with yellow lips and peg-like teeth on each corner. When its mouth is open, its large tongue and throat are visible. When the mouth is closed, its top teeth may or may not show. It has a stubby nose above its prominent mouth. It has two circular ears on the ends of short stalks. The ear insides ringed with black and purple, and the back of the ears ringed with black. It has arms with three fingers and short legs with two peg-like toes. There is a yellow circle on each foot's underside. Its back has a yellow pattern that resembles sound waves.
Loudred has a powerful voice that can blast wooden houses into splinters and knock over trucks. Its round ears are used as loudspeakers and it becomes temporarily deaf after it stops shouting. It stomps its feet on the ground to build up power. It lives in caves.