Green Chocobos are a type of Chocobo, which is a mob added by Chococraft by Torojima. It is generally regarded as a Second Tier Chocobo color as it is created by breeding two Yellow Chocobos (which are First Tier). Green Chocobos can be bred with Blue Chocobos to produce a Green, Blue, or White Chocobo. If a mutation occurs, it will produce a White Chocobo, which is Third Tier. To increase the chances of mutating and producing a White Chocobo, you can use Golden Gysahls in the breeding process.
Green Chocobos have the ability to climb, which means they do not have the need to jump when ascending a block level. They are slightly faster than their yellow cousins.