There is no planet that is literally made of blood. The concept of a "blood planet" is more of a science fiction idea. However, some planets may have atmospheres or surfaces that appear reddish due to various geological or atmospheric factors.
For example, Mars, often nicknamed the "Red Planet," has a reddish appearance due to the presence of iron oxide (rust) in its soil and rocks. The rusty color is similar to the color of blood, but it is not actually blood.
In science fiction, the idea of a blood planet might be used to represent a planet with a violent history, or a planet that is somehow connected to life and death.
