Slice both ends of the prickly pear off. Make one long vertical slice down the body of the prickly pear. Peel back the skin, by pushing it back with a knife or your hand. The skin should come right off, and you should be left with just the prickly pear.

Place peeled prickly pears in blender with 1 cup of water. Blend at the lowest speed for 1 minute.

Strain and discard the seeds and pulp.

Place prickly pear juice back in the blender, with orange juice, and agave syrup. Blend until smooth.

Serve over ice.