Mars is an unlockable stage in Zebra Evolution, where new types of zebra become available, pooping rubies instead of coins.

Rather than purchasing zebras or a crate delivery service, you must exchange rubies with the alien for alien zebra eggs.

There are 12 different zebras available here, across two parts of Mars:

Baby Alien Zebra Right arrow Evolved Zebruus Right arrow Diskette Right arrow Chazzam Right arrow Zplosh Right arrow Fifi of Provibex Right arrow
Zznaek Right arrow Anittas Right arrow Vibez Right arrow Biuti Right arrow Kyozen Right arrow Belzebroo

The Belzebroo can be traded with the alien for 30 diamonds, but this will lower your rubies per minute stat.