An Abnormality from Project Moon's works (Lobotomy Corporation, Library of Ruina, Limbus Company), appearing in Lobotomy and Library as of 01 Apr 2025.

Punishing Bird, also called "Small Bird", appears as a tiny white bird-like creature with a crimson-red belly, and is closely tied with two similar avian Abnormalities, Big Bird and Judgement Bird. In Lobotomy it is classified as a HE (middle-level) Abnormality - the lowest of the Birds - and can combine with the other two birds to create another Abnormality, Apocalypse Bird; in Library they are associated with the Binah floor and are fought both as individual Abnormalities and collectively as part of the floor's Realisation boss fight.