The Sand People - S1.E42

Lotor sets up his command base on a desert planet, planning to enslave the peaceful Sand People and turn them into Robeasts. A local researcher, Professor Sawa, realizes what's happening and calls in the Voltron Force. Princess Allura meets with the Sand People, and sees that they are innocent and childlike. She gives one her bracelet as a present. But when Lotor attacks with his new Robeast, Allura recognizes the bracelet on the monster's arm.