Before eating its prey alive, the ampulex dementor wasp paralyses its prey not by locking up its muscles but by stealing its free will.

A single sting of the wasp's venom, injected into the belly of a cockroach, blocks the receptors of the neurotransmitter involved in spontaneous movement. In this zombie-like state, the stupefied cockroach is still capable of movement but can no longer control its own body, leaving it to the mercy of its hunter.

Ampulex Dementor, the soul-sucking "dementor" wasp. Credit:WWF

Named for the fictional soul-sucking dementors in the Harry Potter books, Thailand's ampulex dementor is just one of the 139 new species discovered by scientists in the Greater Mekong region last year, according to a new report by WWF.

It's in impressive company. The world's second longest insect, a tiny bat with fangs so long they make Dracula look friendly and a thorny frog that switches from yellow and brown during the day to snazzy pink and yellow at night were also among the new species.