Blood-thirsty is a term often used to describe a person or animal that has a strong craving for blood or violence. However, there are several other synonyms that can be used in place of this term. Some of the most common alternatives include ferocious, savage, ruthless, barbaric, and cruel. Other similar terms include brutal, merciless, and aggressive. Each of these synonyms conveys the idea of a person or animal that is violent or has a strong desire to injure others. While these terms are often used interchangeably with blood-thirsty, they each have their own unique connotations and shades of meaning.