Pañcuposatha Jātaka (No.490)
Once four animals — a wood pigeon, a snake, a jackal, and a bear lived on friendly terms with the Bodhisatta, who was an ascetic, and, with him as their teacher, they all kept the uposatha to rid themselves of their sins and desires. The pigeon had yearned too much after his mate, who was killed by a hawk; the snake had killed a bull, which trod on it; the jackal had lost his hair by clinging too long to an elephant’s corpse; the bear had received many blows when he visited a village for food; while the ascetic himself had been proud until visited by a Pacceka Buddha, who pointed out to him the folly of pride.
Anuruddha was the pigeon, Mahā-
The Jātaka was related to five hundred lay disciples (upāsaka) to encourage them to keep the fast days. J.iv.325 ff.