If you mean someone who bites:
* Mordu: This is the most general term for someone who bites, but it can also mean "bitten".
* Personne qui mord: This literally means "person who bites".
* Mordeur: This is a less common word, but it specifically means "biter".
If you mean someone who is biting or criticizing harshly:
* Critique acerbe: This means "acerbic critic".
* Personne sarcastique: This means "sarcastic person".
* Personne mordante: This literally means "biting person" and can refer to someone who is sarcastic or critical.
If you mean someone who bites things like a dog:
* Chien qui mord: This literally means "dog who bites".
If you're talking about a tool that bites:
* Mors: This word refers to a bit, like the one used in a horse's mouth.
Always consider the context of the situation to choose the most appropriate translation.