Identify one key feature of a tiki cocktail.

The key feature of a tiki cocktail is the use of tropical fruits and flavors. Tiki cocktails are known for their vibrant, fruity profiles, often incorporating ingredients like pineapple, orange, coconut, and other exotic fruits. This characteristic not only aligns with the overall theme of tiki culture, which is inspired by Polynesian and tropical aesthetics, but also enhances the drink's appeal by creating refreshing and complex flavor combinations.

In addition to the emphasis on fruity ingredients, tiki cocktails often feature rum as the primary spirit, further tying into the tropical vibe. The distinctive use of tropical fruits is what sets tiki cocktails apart from other cocktail genres, making it a defining feature. Other options, while they may sometimes appear in specific cocktails, do not capture the essence of tiki cocktails in the same way that the celebration of fruity and tropical flavors does.