Actinodendron glomeratum

Large anemone with robust tentacles, covered in clusters of vesicles. Green color at the mouth, with numerous dark dots, running up the branches. When touched it can expel water and retract into the bottom very quickly.
Up to 30cm in diameter.
It can be found on sandy bottoms in the entire Indo-Pacific region, in a depth range of 0-5 meters.
It can deliver a painful and powerful sting. It pays to watch these anemones closely, often they have species of Periclimenes shrimps on them.