The Watchers then took a vow never to interfere with other civilizations. Despite this, the Watcher Uatu has revealed himself to the superhero team the Fantastic Four, telling them of his race. In his first appearance, he made them battle the Red Ghost and his Super-Apes for control of the Moon.

Did the Watcher interfere in what if?

Long before Marvel's What If...?, Uatu the Watcher broke his vow of non-interference in the comics, helping the heroes save Earth from destruction. Although he sees all, Uatu the Watcher has made it clear that he is never to intervene in mortal affairs.

Can the Watcher interfere Marvel?

Marvel's Watcher is known for adhering to a strict oath never to interfere with the goings-on of mortal beings...but he's also known for repeatedly breaking that oath again and again.