FusionDex

If Cactreon doesn't get enough moonlight, it becomes particularly irritable and starts threatening other Pokémon with the green spines on its body. It prefers to lead a nomadic, solitary life in vast deserts rather than settle in one place.

Cactreon evolved from exposure to the moon's energy pulses. After spending thousands of years in harsh deserts, its blood transformed into the same substances as sand.