Though it will grow up to be a fairly unassuming-looking bird, for the first 18 days of its life a cinerous mourner (Laniocera hypopyrra) is clad in bright orange feathers. These feathers allow the chick to look like a toxic caterpillar, protecting it from predators. In addition to the coloring, the bird actually looks long and slender like a caterpillar as well!
Check out this video from New Scientist: