A video of a live parasite unravelling itself from the carcass of a spider has clocked up over a million views on YouTube.

Posted by Australia-based user BaskWith2, it comes with the following explanation: “Ok so I was just editing my latest montage and this huge spider came out, so I sprayed it and killed it, then this fricken alien worm came out of it!”

The clip is appropriately titled “WTF IS THIS?!?”

Among the thousands of horrified comments is speculation the “alien worm” is “a baby flying spaghetti monster”, an extra from The Thing, and an energetic strand of chow mein.

However several contributors were able to stop screaming for long enough to correctly identify it as a parasitic nematode – aka a roundworm.

What’s more, Harvard University entomologist Dr Brian Farrell told The Huffington Post human beings are infested with thousands of tiny nematodes.

He said: “Most have no obvious effect on us, and we are mostly unaware of their presence, but a few are large enough to cause diseases such as trichinosis."

Pass the sick bucket.

(By the way, according to NHS Direct, a roundworm infection occurs if someone swallows the microscopic eggs in contaminated food or water - or touches contaminated soil. Symptoms can inclue a dry cough as well as a high temperature but infections can be treated with medication. There are around 80 cases of roundworm infection reported in England, Wales and Northern Ireland each year)

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  • Strongest Animal

    The rhinoceros beetle (pictured) can push around 850 times its weight.

  • Largest Invertebrate (Land)

    The coconut crab weighs about 6.6 pounds and its legs can span up to two and a half feet Liz Hall from the Melbourne Aquarium inspects Coconut Crab as he takes possesion of a coconut in Melbourne, 19 December 2006. They Coconut crab (also known as the Robber Crab) are the largest living crab in the world and can climb coconut trees to harvest coconuts which they can break with their huge nippers and have been gruesomely know to feed on injured or unconcious people in the bush. (William West, AFP / Getty Images)

  • The giant squid is the world's largest invertebrate, and the largest ever measured was 59 feet long. Giant squids also have the largest eyes of any animal, each one about the size of a human head.

  • Smallest Mammal

    The etruscan shrew is the smallest mammal (by weight) in the world. The smallest animal by skull size is the bumblebee bat.

  • Most Venomous Animal

    The sea wasp jellyfish (pictured) has enough venom to kill 60 adult humans. Photo: <a href="http://www.flickr.com/people/65578066@N00" target="_hplink">Guido Gautsch/Flickr</a>

  • Longest Migration

    Arctic terns migrate about 11,000 miles to the Antarctic each year...and then come all the way back! An Arctic Tern dives down to protect its nest on June 24, 2011 on Inner Farne, England. (Dan Kitwood, Getty Images)

  • Loudest Animal

    Blue whales' low-frequency pulses can be heard over 500 miles way. At 188 decibels, these sounds are louder than a jet engine. In this picture taken on March 26, 2009, shows a blue whale swimming in the deep waters off the southern Sri Lankan town of Mirissa. (Ishara S. Kodikara, AFP / Getty Images)

  • World's Most Extreme Animals

    North African ostriches run up to 45 miles an hour, making them the fastest land bird. They are also the biggest, weighing up to 345 pounds. An african ostrich eats at the Addo National Elephant Park, north of Port Elizabeth, on June 24, 2010. South Africa is hosting the 2010 FIFA World Cup. (Patrick Hertzog, AFP / Getty Images)

  • Fastest Bird

    Peregrine falcons dive toward their prey at over 200 mph. A young male Peregrine Falcon eats meat taken from the protective glove of Taronga Zoo bird trainer Erin Stone (unseen) following a short flying lesson in Sydney on December 9, 2009. (Greg Wood, AFP / Getty Images)

  • Fastest Fish

    Sailfish can swim at speeds of up to 68 mph, although experts disagree as to just which species of sailfish is the fastest. Sailfish jumping out of the water on January 16, 2006 in the Florida Keys, Florida. (Ronald C. Modra, Sports Imagery / Getty Images)

  • Fastest Mammal

    Cheetahs can run at speeds up to 70 mph. Majani, a 2-year-old male African cheetah, exhibits lighting speed Friday, March 19, 2004 while chasing a mechanical rabbit at the San Diego Zoo's Wild Animal Park as part of the Park's environmental enrichment program. (Ken Bohn, San Diego Zoo / AP)

  • Longest Lifespan

    Three giant tortoises are estimated to have lived over 175 years, with one estimated at a whopping 255 years. Image: Harriet, who died in 2006, was thought to be the third longest-lived tortoise on record. <a href="http://www.flickr.com/photos/doctorow/123660557/" target="_hplink">Cory Doctorow/Creative Commons</a>

  • World's Most Extreme Animals

    African elephants are the heaviest and second tallest land animals. Large males can exceed 13,000 pounds and are 12 feet tall at the shoulder. This photo made on February 10, 2011 shows an elephant in Tsavo west national park, some 350 kilometres southeast of Nairobi. (Tony Karumba, AFP / Getty Images)