Complex sentence: The green-and-black poison dart frog is one of the most variable of all poison frogs in appearance; some have black or brown splotches, others are dappled, or have "splashes" of black, like "Oophaga sylvaticus".
Split into simpler sentences: The green-and-black poison frog is one of the most variable of all poison frogs in appearance. Some have black or brown splotches, others are dappled, or have "splashes" of black, like "Oophaga sylvaticus".