Working as a team with his father, Moonwatcher protected the Echidnas for many years. Moonwatcher was the first Guardian to be brought to Haven by his father, where the two would rotate their duties of protecting Echidnaopolis. He became a member of the original Brotherhood of Guardians along with his son Harlan - the name of the group having been conceived by his grandson Rembrandt. Not much is known about Moonwatcher’s tenure as Guardian except that he defeated the Dark Legion during one of their many breakouts of the Twilight Cage, sending them back to their imprisonment. Moonwatcher deeply mourned Aaron's death along with the other Brotherhood members, and he, along with his son Harlan, felt that Rembrandt's new method of training Jordan was wrong and that they should all participate in his training, though Steppenwolf pointed out Jordan should learn slowly before his responsibilities were increased.
Dying at some point of either old age or other causes, he would appear at Knuckles the Echidna's funeral along with the other deceased Guardians during Knuckles' brief stay in the afterlife. Moonwatcher mistook Chao messengers from Aurora as arriving to guide his father to the Chaos Force, his son Harlan, however, realized that they were coming for Knuckles.
- Moonwatcher is one of the few members of the Brotherhood that wears a full-out uniform.
- Moonwatcher is very similar in appearance to Star Trek: The Next Generation character Geordi La Forge.