The title character was the first Martian to visit the Earth.

Every issue, including the last one, had a cliffhanger ending.

[2] Besides the title character, other characters are Orbi (Cosmo's astronaut companion), Professor Thimk (the scientist who invented the Martian spaceship, but was not on it when it took off from Mars), and Astra (Cosmo's girlfriend).

[3] A reboot of the series, titled Cosmo the Mighty Martian, began publication in January 2018.

The new series is written by Ian Flynn with art by Tracy Yardley and Matt Herms, all of whom previously collaborated on Archie's Sonic the Hedgehog comic series.