The variatus platy grows to a maximum overall length of 7.0 cm (2.8 in). In the wild, they are olive in colour with black marbling or spots on the side of the caudal peduncle. Large males show blackish blotches on the dorsal fin. Unlike some other members of the genus, X. variatus has no claw at the tip of the fifth anal fin ray. The fourth pectoral ray shows well-developed serrae (saw-like notches). They typically have 20 to 24 lateral scales, 10 to 12 dorsal rays and two rows of jaw teeth.