With the Halloween weekend rapidly approaching, it seems as though one of poker’s biggest names may be playing in costume.

The player in question is “raiseonce”, who has become a frequent fixture at the nosebleed tables over at PokerStars. After appearing sometime during 2009, the mystery man has made a name for himself with a hard-driving, aggressive style. This, combined with several other factors, has led many online wizards to predict that raiseonce is, in fact, Full Tilt pro Phil Ivey.

Why Ivey? He’s obviously got the money required to sit in at the $1,000/$2,000 tables, and is widely known for his aggressive play. There are also some timing cues to consider – both players seem to exhibit a fondness for short sessions, playing at only a few tables at a time. There’s also the Las Vegas address, which would instantly put him in the right neighborhood.

Another fact to consider comes in the form of money management. Ivey is generally known to excuse himself after losing two buy-in’s, limiting himself and protecting against losses. While raiseonce’s tendencies in this area cannot be confirmed, he is thought to operate under similar parameters.

As a member of Team Full Tilt, Ivey isn’t supposed to get chummy with the competition. This could be his way of getting around the issue.

But assuming it’s not Ivey, who else could raiseonce be? Some have suggested Patrick Antonius as a likely candidate, while others believe it could be Tom Dwan. Antonius would be the more likely of the two, but both have several factors which would seem to rule them out of the running. Todd Brunson has also been mentioned as a player who would fit the raiseonce mold.

One thing’s for certain – as the clue’s continue to pile up, the mystery only get’s more interesting.