Which ingredient is NOT typically found in a Mojito cocktail?

The ingredient that is not typically found in a Mojito cocktail is tequila. A traditional Mojito is made with white rum as its primary spirit. The other essential ingredients of a Mojito include fresh mint leaves, sugar (or simple syrup), lime juice, and soda water. The mint provides freshness and aroma, while the lime juice adds acidity and brightness to the drink. Soda water is used to top off the cocktail, providing a light effervescence. Tequila, which is made from agave, is not a standard ingredient in this Cuban cocktail; instead, its use is more aligned with drinks such as Margaritas. Thus, tequila does not belong in a Mojito, making it the correct answer to the question.