 If the horns didn't provide a camouflage benefit in active hunters, they might not evolve as often as in sit and wait predators. With the help of an evolutionary tree, the team found that lizards and snakes independently evolved horns on the top of their heads, eyebrows, or snouts at least 69 times. That said, horns or spikes on these reptiles aren't the norm and only adorn less than 10% of the species the scientists analyzed.