https://www.pcgamer.com/rabbids-easter-egg-found-in-rainbow-six-siege/

Ubisoft love to sneak references to their games into their other games. Far Cry New Dawn, to pick a recent example, contains nods to Splinter Cell, Assassin's Creed, and the rabbids who have gone from enemies in Rayman to somehow become Ubisoft's weird mascots. And now, players have found a reference to them in the new Rainbow Six Siege map as well.

Over on Reddit you can see a demonstration of how to find it. They're painted on the inside of a log in the Outback map. As an Australian I'm not sure how to feel about this. Yes, we do have a lot of strange animals in this country. No, lapins crétins are not among them. (That's their French name, it means "idiotic rabbits".) I do have fond memories of that Wii minigame where zombie rabbids in scuba gear come out of the ocean and you have to fill their masks with carrot juice to drown them. If they invade Siege more fully, that's the tactic I recommend.