The Green April (초록 사월, Chorok Sawol; "Green Fourth Moon") is a weapon of the 13 Month Series. It was first owned by Anak Zahard's mother who was a Princess, then by Anak herself and is currently in the possession of Yuri Zahard.
It is a Hook capable of elongating and as it's also a Compression Weapon; Ignition will decompress part or all of it. When Ignited, the Green April could turn a place into "a massive forest". The Green April is a 7B-rank Hook, which most likely becomes A-Rank when Ignited.
Its original form has only been glimpsed, it has sharp teeth and short, wavy hair. It might be human, non-human or even demonic. The weapon's personality is not known, as its form has been seen so little. It seems quite sadistic, and enjoys being used in combat.