Prometheus's Clique: Seers
These kids spend all their time at lunch with tarot cards, crystal balls, fortune cookies, and, most importantly, astrology books. If you want to get a hint about what's on the horizon for your life, these are the ones to go to. You'd better think twice before you start asking a seer a bunch of questions, though. The truth is you might not like what you hear. Prometheus was one of the original members of this clique. Being the god of forethought, he totally knows everything that's going to happen—ever.
Chiron is a centaur, meaning he has the upper body of a man and the lower body of a horse. Besides being a famous mentor for lots of heroes, he's also an awesome prophet. All he has to do is look up into the stars, and he can tell you everything that's going to happen.
This blind prophet of Thebes can see into the future like nobody's business. His main method of divination is augury, the art of predicting the future through the flight patterns and songs of birds. He can also divine the future from the smoke of burnt offerings and even receives visions straight from the gods. This prophet of prophets shows up in tons of ancient Greek tragedies and is most famous for his role in the Oedipus plays.
Oracle of Delphi (Apollo)
The Oracle of Delphi was the most reputable place to go in ancient Greece if you wanted to get a little peek into your future. Usually, one young girl acted as the prophetess. Her duties included hanging out in a temple all day, inhaling volcanic fumes that drifted up through the earth, and having crazy trippy trances in which people believed she could catch glimpses of the future. The Oracle was a temple of Apollo, the god of prophecy, who was said to be the guy sending the visions. It's said that Apollo claimed the Oracle, which used to belong to Gaia, the Earth, after killing Python, Gaia's son, who was also a giant snake. Yowza.
Mamitu is a Mesopotamian goddess who lives in the Underworld and knows everyone's fate. Of course, she's also the one who decides everybody's fate, so maybe her prophesying ability isn't quite as impressive as it sounds.