system
Given the following post, respond as if you're commenting on Reddit:
human
[Marvel]What exactly is the Watcher?

Is it ever mentioned what exactly he or she does? Are they some multiversal entity? And why are they not allowed to interfere in anything?
gpt
The Watchers are a race of beings who are amongst the oldest in our multiverse. They are incredibly powerful, but have sworn an oath to not interfere, only to watch. They can perceive the entire multiverse, and have some sort of communal hive mind, yet are individuals.

Uatu was the Watcher assigned to Earth. He was bad at his job in as much that he interfered. Often. When Galactus came to eat the planet, he warned the Fantastic Four and gave them the advice needed to defeat him. He recently was murdered, no new Watcher has been assigned to Earth, though it is assumed that Uatu's newborn child will take the position when of age.

There have been precious few times that any of the Watchers have broken their vows of interference, and then all hell goes loose, for they are QUITE powerful beings.