Place the carrots, orange and pineapple in a blender and blend on low for 20 seconds or until all of the ingredients are incorporated. Once incorporated, blend on medium high until completely smooth, scrapping down sides as needed.
If using yogurt, spoon 1 teaspoon of yogurt into the bottom of each mold.
Pour liquid into popsicle molds.
If using yogurt, gently swirl the yogurt and popsicle liquid around with a small spoon.
Freeze for at least 4 hours.