Alien Baltan are arthropod-like aliens from the Planet Baltan. They are one of the Ultraman Series' most popular antagonists and are noted to have tried to attack Planet Earth and the Ultras themselves several times.

The Alien Baltans' planet was destroyed by a mad scientist using nuclear weapons, so they sought out a new world to live in. The 2.03 billion Baltans shrunk down to microscopic size and traveled through space, until their gravitational thrusters malfunctioned. The Baltans landed on Earth for repairs, but soon found the planet suitable to their needs, and decided to conquer it. The single normal-sized Baltan began to infiltrate a science base, as it searched for parts to repair the ship, freezing anyone who got in its way. The Science Special Search Party began to investigate, and Arashi was frozen by the Baltan. After Ide attempted to converse with the Baltan, it led him to the roof for negotiations. Using its spectral powers, it took hold of Arashi's body and spoke to Ide and Hayata, who just arrived. Upon revealing their plan and denying co-existing with the humans, the Baltan left Arashi and then grew to gigantic size.