Although it always pretends to be a tree, its composi tion appears to be closer to a rock than a plant.
It disguises it self as a tree to avoid attack. It hates water, so it will disappear if it starts raining.
If a tree branch shakes when there is no wind, it's a SUDOWOODO, not a tree. It hides from the rain.
SUDOWOODO camouflages itself as a tree to avoid being attacked by enemies. However, because the forelegs remain green throughout the year, the POKéMON is easily identified as a fake during the winter.
It mimics a tree to avoid being attacked by enemies. But since its forelegs remain green throughout the year, it is easily identified as a fake in the winter.
— Pokédex entries (via PokeAPI)