Crab enemies appear throughout the Seiken Densetsu series. There are two different types of crabs: Pincher Crabs and Metal Haggars. Pincher Crabs are small terrestrial crabs which attack with their claws. Metal Haggars are giant clawless crabs which attack by jumping around or breathing stuff out at you. A Full Metal Haggar appeared in SwoM being ridden by a Poisonous Vine enemy.
Death Crab
These crabs live on the coasts around Wendel. They attack by throwing their claws at you.
Full Metal Haggar
Unlike the Metal Haggars which follow it, this one has claws.The battle with this crab takes place in the cave North of Jadd. The fight is in a very confined area, but the crab cannot hit you if you stay in the upper left corner. His eyes are his weak points, a trait which would stay common throughout the series.
Steamed Crab / Death Crab (J)
In SoM Steamed Crabs are classified as Insects.
They live mainly in the Winter area of The Great Forest, but are also found in the Summer and Spring areas. They attack by throwing their claws in a circle around them. They will occasionally get angry and start ramming you.
Metal Crab
In SoM Metal Crabs are classified as Machines.
Metal Crabs are far and few between in SoM. They are found in the Mana Fortress in only a few places, most notably the very entrance. They attack with their claws like the crabs before them, but they also breathe out a harmful breath. They usually start off a fight by casting Light Sabre. Metal Crabs drop a Bow orb.
Full Metal Haggar
The Full Metal Haggar is the first real boss enemy you face in SD3. It has captured the spirit Wisp, and is able to use its powers. It can heal itself as well as cast Holy Ball on you. It will usually poison you with its poisonous breath, and it will use a special attack where it dive-bombs all of your characters. Its eyes can shoot lasers, but as it takes more and more damage its eyes will close.
In LoM Crabs are classified as Aquatic.
Pincher Crab / Death Crab (J)
The normal Pincher Crab enemies are colored blue and are found in different caves as well as on the beach. They are described as grumpy creatures. They attack by shooting their claws out to pinch you. Pincher Crab pets will protect you from being put to sleep. Millions of red Pincher Crabs live on Madora Beach in LoM. While questing on Madora Beach you can chase the red Pincher Crabs around and crush them. Depending on how many you crush you get a different message from a special crab at the far side of the beach.
Full Metal Haggar
The Full Metal Haggar appears during the “Summer Lovin” quest as a boss for no reason. He jumps around and spits bubbles at you. It is interesting to note that he gets counted as a crushed crab when you beat him.