"Rejected" page of the script.
The image of a "mapinguari" from DJ Dan's site. In reality, it is an exhibit of a giant ground sloth (extinct species) at Illinois State Museum.
Mapinguari is a possibly-rejected explanation of what the monster really is. This page is one of the easter eggs in oceanic-air.com, a site operated by ABC rather than Lost's creative authorities. Therefore the canonicity of this website's contents are disputed by fans.
The Mapinguari is a giant ground sloth-like creature of folk legend, similar to the Loch Ness Monster, Bigfoot or Chupacabra, and is reputed to live in the Amazon jungle of South America. However, the Mapinguari is normally not associated with Australia.
Holy. Freakin'. Lord. Huge. Mechanical AND Biological. Godlike and profane. A massive, multi-tentacled robotic beast resembling a primordial mapinguari - only partially obscured in a cloud of acrid smoke.
(Handwritten: NO! NO! NO!! NO MAPINGUARI! NOT YET!)
The Lost Experience
In addition, a mapinguari-like creature can be found at DJ Dan's website on the "Mythic Beastie Sighting" page. Despite it also being featured on the DJ Dan website, it is most likely that this is just the producers pulling our legs, as the black smoke has no appearance similar to a Mapinguari: also the caption "Mythic Beastie Sighting" seems almost like a joke.
Once Upon a Time
In the TV series "Once Upon a Time", which is known for portraying references to the universe of Lost, King Midas makes reference to having a slain Mapinguari in his castle. (Ep. 06)