Martian Master

The Martian Masters are a race of cephalopod-esque race of extraterrestrial beings who invaded Earth in the early 20th century, launching from the planet Mars but (despite their name) not being native to the planet.

Biology
They resemble cephalopods with red skin, green tentacles and black eyes. They also seem to have weak immune systems, as their invasion was easily thwarted by several of the invaders being wiped out by Earth's diseases.

Reproduction
They appear to reproduce by budding, as their offspring grow on the outside of their bodies, like fruit on a tree.

History
They were first discovered when they invaded Earth in the early 20th century, an event known to many as the "War of the Worlds", which was fictionalized by H.G. Wells in his novel of the same name. This invasion was thwarted due to their lack of immunity to Earth's diseases.