1. Cut frogs' legs apart. Pour milk into pie plate or other shallow dish; combine flour, salt,and pepper on sheet of waxed paper. Dip frogs' legs in milk, then in flour to coat them well.
2. In 12-inch skillet over medium heat, in 4 tablespoons hot butter or margarine (1/2 stick), cook frogs' legs, several at a time, turning once, until fork-tender and lightly browned, about 5 to 8 minutes. Remove to warm platter; keep warm while cooking remaining frogs' legs, adding more butter or margarine to skillet as needed.