First of all let’s define what is a Black Body?
Black Body is the type of ideal body that either absorbs all the incident radiation or emit black body radiation but it does not reflect. It absorbs radiation regardless of frequency or angle of incidence.
A perfect ideal black body does not exists in reality. It is just hypothetical black body.
Near Black Body Objects
Lamp black also known as carbon black is produced by incomplete combustion of petroleum products. If you paint a surface using lamp black it can absorb 97 percent of the incident light and can be considered as a near example of black body.
Stars and Planets
All objects including stars and planets radiate energy which depends on their temperature. Cooler stars are red in color. Our sun is hotter star which emits most of it’s radiation in yellow / green part of the spectrum.
Nothing escapes once it enters the event horizon of a black hole, thus making black hole an ideal black body. It absorbs all the light that hits the event horizon. Also black hole emits black body radiation which is known as Hawking radiation.