XYZ System

Planets X, Y, and Z, collectively, the XYZ System or The Stage Planets, is a celestial system consisting of two earth-sized planets and six moons. All three are capable of harboring intelligent life, but none have been proven to possess such.

Planet Z, despite the name, is actually in orbit around Planet Y, and one penguin swears that there is not only life on that moon, but an entire imperialistic civiliation.

Inhabitants
None of the planets harbor intelligent life, or, at least, no life has been discovered on these planets. However, speculation exists, and all three planets have a chance of extraterrestrial beings.

Planet X's soil composition is theorized to be mostly iron, due to its red color from telescopic views. Even the water is red (the dark red is thought to be water) because of the oxidized iron on it. It has one grey moon, possibly a captured satellite.

Planet Y is green. Four of its five moons are also green, which led astronomers to theorize that they formed with Planet Y. Planet Z, however, is grey. It may be a captured satellite.

Planet Z- which is actually a moon -has horrendous tidal forces at work by its host, Planet Y, and the other four moons orbiting said world. Plus, there is no water othere. There is no way that life could exist on Planet Z, unless the creatures somehow adapted to life without water.