True to their name, red foxes generally range in color from yellowish red to reddish brown. Gray foxes, however, can also have red patches of fur, which sometimes makes it difficult to distinguish between the two species. The tail serves as a clear marker of difference: the tail of the gray fox has a black tip, while the tail of the red fox is white. Both species typically weigh between 6 and 15 pounds, though some foxes can grow as large as 30 pounds in weight. Foxes are usually about 2 feet tall and 3 feet long, including the tail.
More information on what a fox looks like.