It were supposed to be 2 named rabbits, Spaz and Lori. But the dev didn't get permission to implement it. In the end he secretly snuck in 2 extra nameless rabbits. He doesn't make clear whether there were supposed to be rabbits in that area of the game before he added those.

Definitely a cool story, but not really an easter egg by itself without the dev explanation.

Still thanks for sharing it!