Complex sentence: The eastern foxsnake is often misidentified as the copperhead, "Agkistrodon contortrix", due to their similar appearances, or as the eastern massasauga, "Sistrurus catenatus", because they often rattle their tails similar to rattlesnakes as a form of mimicry.
Split into simpler sentences: The eastern foxsnake is often misidentified as the copperhead, "Agkistrodon contortrix" or as the massasauga rattlesnake, "Sistrurus catenatus". They often rattle their tails similar to rattlesnakes as a form of mimicry.