I emailed a few scientists and one has replied that this is "caterpillar of a moth of the family Limacodidae".
Can't confirm that, but it's kind of hard to prove that it isn't. Wikipedia says: "They are mostly tropical, but occur worldwide, with about 1000 described species and probably many more as yet undescribed species." Under "Caterpillars" it says: "The larvae are typically very flattened, and instead of prolegs they have suckers[2]. The thoracic legs are reduced, but always present and they locomote by rolling waves rather than walking with individual prolegs. They even use a lubricant, a kind of liquified silk, to locomote on[3]. . . . . The larval head is concealed under folds." Darren Addy Kearney, Nebraska -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.