01 - Combine the drained lychees, lychee syrup, coconut milk, lime juice, and agave syrup (if using) in a blender. Blend until completely smooth and frothy, about 30-45 seconds.
02 - Fill two tall glasses with ice cubes, leaving about 1 inch of space at the top.
03 - Pour the blended coconut-lychee mixture over the ice in each glass, dividing evenly between the two servings.
04 - Top each glass with extra lychee fruit, fresh lime slices, and mint leaves if desired. Serve immediately while cold.