The producers of ABC's FlashForward have said the kangaroo has become a significant part of the show's first season: Co-creator David S. Goyer says the animal's appearance started out as a simple gag but will gain more importance as the show develops.

The 'roo was first seen in the pilot episode, in the aftermath of the blackout in downtown Los Angeles. We saw it again last week, hopping along with trick-or-treaters.

Naturally, FlashForward's devoted fans have come up with several theories about the marsupial's role in the sci-fi drama. Here are a few of the best. FlashForward airs Thursday nights at 8 on ABC.

It's an animal thing. ArisuCheddar at ABC.com reminds us that animals appear to be relevant to the flash-forwards and a possible indicator that this has happened before. Birds have fallen from the sky or crashed into windows, although Arisu points out that the kangaroo seems pretty alert. It doesn't look as if it just woke up from a hopping accident. "I see it as just another indicator that this was a concerted effort and a deliberate act," ArisuCheddar writes.

The kangaroo is a symbol that the future is not set. ABC.com poster yoda2714 speculated that the hopping kangaroo should clue viewers in that the flash-forwards were just a jump in consciousness. The characters should stop worrying about the future, because it was just a one-time hop. "It could mean that continuity is not possible," yoda2714 writes. "i.e., there will be no connection from 10.6.09 to 4.29.10 because of the 'hopping' effect of the FFs. Or stated more simply, there may be no in-between in terms of 10.6.09 and 4.29.10, just those two points."

It's a play on words. Mizzllat on TV.com recalls the (disproven) legend of Captain Cook's exploring Australia, at which time "kangaroo" meant "I do not understand you." So the kangaroo could just represent strange things that can't be understood, if the producers are following outdated definitions.

Kangaroos from hell! Nixie_Knox on ABC.com takes Australian wordplay a step further. Since kangaroos are Australian, from the land "down under," "This can be a play on words to represent the 'underworld' and can be symbolic of hell coming to Earth," Nixie writes. "Or perhaps the kangaroo could represent the concept of a demon come to earth."

A mad teleportation experiment caused the blackouts. Nypdretired02 at ABC.com thinks that what caused the blackouts was a science experiment gone wrong. If that experiment involved teleportation, that could result in a kangaroo transporting to L.A. instead from its native Outback. That would also hint at why people's thoughts jumped to April 29.

The kangaroo caused the blackouts. Tvlurk.com poster flashart has a similar "mad experiment" theory. Whether it's teleportation or not, something left a door in time and space open. That's where flashart thinks the kangaroo walked through to get to L.A. "Trace the kangaroo's path and find out where the door is," flashart writes.

Australia did it!. Speaking of all these evil experiments, whatever had a side effect of sending a kangaroo to L.A. must have originated in Australia. Chinese experiments would've sent pandas to L.A. instead. Kris, posting at TVSquad, joked that either Australia or the local zoo is involved, but Kris may be onto something with Oz.

It's connected to Dylan. LOSTfantasygirl at ABC.com noticed that young Dylan (Ryan Wynott) had a stuffed kangaroo on his dresser when Lloyd (Jack Davenport) went to his son's room. Dylan already found the Benford house from his flash-forward. Maybe the kid will make the kangaroo connection too.

It's all in Mark's head. Has anyone else actually acknowledged the kangaroo? Mark (Joseph Fiennes) saw it downtown and then again in the suburbs—although Aaron (Brian F. O'Byrne) and Charlie (Lennon Wynn) were with Mark the second time, so they noticed it too, right?

It just broke out of the zoo. There was a lot of chaos during the blackouts. Goyer said that he imagined an animal transport van crashing and freeing the kangaroo. Other literal-minded viewers like LostEmissary at Flashforwardtv.com suggest a zookeeper blacking out and leaving the cage open. Heck, if a plane crashed into a zoo it could have knocked the cages open, too.

It's not a kangaroo at all. Australian poster bookwormy342 at TV.com claims we're all wrong. It's not a kangaroo, it's a wallaby. Great, now we have to start all over.