Seeing as how it fires water from its claw, Clauncher is likely based on a pistol shrimp. Its blue color scheme may be based on the Procambarus alleni, though it may also be a reference to mutated American lobsters.
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Clawitzer appears to be based on a pistol shrimp, with its oversized claw and its ability to expel powerful blasts of water from its claw. Its deep blue coloration may be based upon Procambarus alleni, though it may also be a reference to mutated American lobsters. Its curved body is often seen in real-world shrimps and prawns, typically when moulting or cleaning.
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They're based more on shrimp than lobsters, but they could draw inspiration from the latter. The only other lobster Pokemon are Corphish and Crawdaunt, both of which draw some inspiration from lobsters. However, they're primarily crayfish, according to Bulbapedia.
Hope I helped!
