Nucleo

Origin
Nucleo is pursued by the Space Rangers, Bob Barry calling Nucleo the "mad Martian with a thousand faces". Sending out Bob Barry and Jim Jones in a scoutcraft to Gamma-3. The pair encounter Nucleo disguised as Spaceman Yelmah. When Yelmah passes out, Barry sends Jim to aid Yelmah. Yelmah locks them in a space trap.

Arriving at Gamma-3, Captain Arax lands the Staritania, a space ship called the "Mighty Monarch of the Spaceways". Nucleo tricks Captain Arax, taking over the Staritania through the guise. Barry and Jim escape the space trap in their spacesuits, floating over to the Staritania. They encounter Stella Dawn in the guise of one of the Galaxy Gals, yet she rebuffs advances by Space Ranger Barry. When the pair go to report to the captain, Nucleo, in his Captain Arax guise, has them immediately arrested by his henchmen. He demands they give the "all well" to the Space Rangers. They do so, but report as each others' names. Speed Lansing takes it as a message something is wrong, reporting immediately to Rex Clive. A group of Space Ranger craft respond to the Staritania, only to discover the Galaxy Gals have the situation in hand, with the later support of Space Rangers Barry and Jones.

Powers and Abilities
Nucleo can immediately take on the appearance of any other person.

Public Domain Appearances
Space Adventures #1