|"Well, I think it's a ridiculous idea. The Clans have lived in these territories for more moons than any cat can remember, and we've never needed the warrior code to tell us how to protect our borders. Clearly some cats are more mouse-brained than others."|
|— Greeneyes in Code of the Clans, pages 105-106|
Greeneyes is a gray tabby she-cat with startlingly green eyes. She is an ancient ThunderClan deputy, serving under Lionstar. In Code of the Clans, she joins her Clanmate, Oatwhisker, when he finds two SkyClan cats at their border after Mottlepaw accidentally crosses it. She asks why they are always snooping around that border, and leaves with her Clanmate, saying that if they want to spy, they won't learn much from the bushes there. It is mentioned that she was only recently appointed deputy.
Greeneyes later comes with her leader, Lionstar, to meet with Rowanstar of SkyClan, and ask why there are always SkyClan cats at their border. Greeneyes accuses the SkyClan cats of spying, because there is nothing at that border, but the start of ThunderClan territory. She tells Rowanstar that the warrior code says nothing about it being a cat's responsibility to keep other cats out, and that it should be obvious.
The warrior, Poppycloud, contradicts her, and says it should be part of the code. Greeneyes glares at her and says she thinks it is a ridiculous idea, and that some cats are more mouse-brained than others. She slants her eyes at Poppycloud and begins to leave with her leader.
- "Why are there always SkyClan cats snooping around here? Is your own Clan so bad that you want to join ours?"
- —Greeneyes questioning the SkyClan cats Code of the Clans, page 102
- "Come on, Oatwhisker. We're wasting our time. If these dumb cats want to spy on us, they won't learn much from the bushes around here. I don't think I've even been to this part of the territory."
- —Greeneyes Code of the Clans, page 102
- "The warrior code says nothing about it being a Clan's responsibility to keep cats out! It should be obvious that the other Clans aren't allowed across the border."
- —Greeneyes about scent marking borders Code of the Clans, page 104