The original sentence is: The frilled lizard has a leathery and spiky frill, like a magic dragon.
This sentence is grammatically correct! It clearly describes the frilled lizard's frill by comparing it to a magic dragon's look, which helps make the image more vivid.
If you want, you could slightly change it to: "The frilled lizard has a leathery, spiky frill that looks like a magic dragon's." Both versions work well.