Wildcat Stinger
["2 1/2 oz. tequila", "2 drops bitters", "1 1/2 oz. dry vermouth", "1 worm (optional)"]
["Combine in a mixing glass half filled with ice cubes.", "Strain into a cocktail glass.", "Garnish with lemon rind, worm or olive."]
["tequila", "drops bitters", "worm"]