Based on color patterns and behavioral similarities, venomous coral snake Micrurus corallinus (Elapidae) may act as a model for two polymorphic species, Erythrolamprus aesculapii (Dipsadidae) and Micrurus decoratus (Elapidae). Plasticine replicas were used to investigate the aposematism of these coloration patterns and whether these species may be part of mimetic complexes in two Atlantic Forest localities in South-east Brazil. Coral replicas were more avoided when set upon a white background, evincing that the pattern may act aposematically in contrast with light substrates. Birds attacked all four patterns equally during the mimicry experiments. Birds of prey, known to be effective in predating snakes, are quite abundant in the study areas, which may have led to this lack of avoidance. Accordingly, they predated more adult-sized replicas, which could be more dangerous. Interestingly, opossum avoided the Micrurus corallinus and Erythrolamprus aesculapii replicas that resembled the model. This suggests that opportunistic predators, as the opossum may be important selective agents in mimicry complexes.