Bemstar appeared in the 1971 TV series called The Return of Ultraman. Bemstar was an energy absorbing armadillo like monster with manta ray features and a stone door like crystal on its chest. from the Crab Head Nebula. He came into the solar system looking for cosmic energy, eating a highly developed space station monitored by MAT. Bemstar soon landed on Earth, attacking a nearby city where MAT counterattacked. Ultraman Jack arrived to do battle, but the beam absorbing alien withstood against most of Jack's attacks, even absorbing the Specium Ray into his gorge.
Jack became extremely weak using up most of his attacks on Bemstar and as a result, he tried to go towards the sun for more energy to recover, but the sun's gravity pulled him in, and causes Ultraman to hurtle towards the sun's atmosphere. Just then, Ultraseven arrived just in time to save Jack! After a brief discussion, Seven gave Jack the Ultra Bracelet, a shape shifting weapon that stuck to Jack's wrist. Jack, now rejuvenated, returned to Earth and fought Bemstar again, this time with greater enthusiasm. He soon used the bracelet and severed Bemstar's arms and head with the Ultra Spark, ending the monster's thirst for energy.
Some time later December 23rd, two days before Christmas, both Bemstar and the monster Seagorath were revived by Alien Nackle to test Jack's strength in battle to reveal what could be exploited as a weakness to defeat him. After Seagorath was defeated, Bemstar was the next to fight Jack. However, he manages to defeat him with the Ultra Bracelet with ease (which is seen as stock footage of their previous battles), not knowing that this was all an experiment to find a way to defeat him.