Liparis marmoratus is coloredlight brown to yellow and has dark brown to reddish spots on its body as well as its median fins. Its body is described as slender but not humpbacked. The festive snailfish's head is wide and has a depression. The head's width is nearly equal to its depth. The mouth is small, with its cleft extending merely below the posterior nostril. Its teeth are trilobed, and each lobe is equally sized. Its upper jaw is slightly longer than its lower jaw. The snout is practically horizontal and blunt at the tip. The fish's chin pores are small and set closely to one another. The festive snailfish's gill opening is also small.