The 'Ryousei Crab' (ロ ウ セ イ キ ヤ ン サ ー, Rōsei Kyansā ) is one of the Dangerous Beasts shown in Akame Ga Kill !.
The Ryousei crab is a big crab. It has six legs and its head resembles that of a lizard. It has eyes more similar to those of a royal crab above its head.
He appeared in a flashback of Chapter 33 in which he appears fighting the members of Elite Seven.