Alien Magma is a brutal alien that has appeared as a recurring antagonist in the Ultraman franchise, first appearing as the main antagonist in the first half of Ultraman Leo.
Alien Magma makes his debut in the first episode of the series. Having previously destroyed Planet L77, Alien Magma came to Earth alongside his subordinates, the Giras Brothers, with the intention of conquering it. He fought Ultraseven and initially had the upper hand in the fight until Ultraman Leo arrived to assist his comrade. After being overpowered by the two Ultras, Magma and his two minions retreated.
Magma and the Giras Brothers later reemerged to cause destruction. They fought Ultraman Leo again, having a much better success this time around. However, with the help of Ultraseven's Ultra Willpower, Leo was able to defeat the Giras Brothers by decapitating them, prompting Alien Magma to retreat.
Alien Magma later returned in episode 30 where he attempts to get Rolan to marry him after she lands on Earth. When she rebuffs him, Magma attacks the peaceful alien, but is fought off by Ultraman Leo after he arrives, prompting Magma to retreat.
After Rolan took a human form and began giving pinwheels to children, Magma showed up to harass her again. Eventually, this culminated in a fight between the two. Alien Magma managed to overpower Rolan, but Leo soon showed up again and beat down Magma before killing him by impaling him with one of Rolan's pinwheels.
A trio of Alien Magma led by a cyborg Alien Magma, called the "Alien Magma Trio", appeared as members of the Guar Army.