Claws are long, sharp finger or toenails on animals. (Between the cheetah’s teeth and claws, the antelope was soon dispatched.)
A clause is part of a sentence, or a part of a contract. (You are in violation of clause b, subpart three, so the contract has been invalidated.)
Claus is Santa’s last name. (Santa Claus)
Keep them straight this way: Claws and Werewolf both have a letter “w”. Santa’s name begins and ends with the letter “s”. When a lawyer invokes a contractual clause, you might want to say, “eek!” Both eek and clause contain the letter “e”.