Froggy

Slur against the Fr*nch. Used because they eat frogs.

Fr*nch "person": Oui oui je'mapple le croisannt en baget
Normal person: Shut up froggy.

Straw Dog

Straw Dogs were used in Ancient China for ceremonies and once said ceremonies ended, were thrown away after their purpose was fulfilled. So, a Straw Dog would be someone who only serves to be used and is then forgotten or discarded. Not to be confused with Straw Man

Person A: I am a terrible person
Person B: Wow! Can I help?
Person A: I really don't care.
(In this scenario, person B would be a straw dog as they are being used with complete disregard. They are a straw dog.)