Three campers have undergone emergency surgery in Mlini, Coatia, after being savaged by the so-called vampire butterfly'.
The three friends, from Ljubljana, Slovenia, had just settled down in their sleeping bags after pitching tent on the edge of the sea on Dubrovnik's Riviera when the butterfly fluttered in.
It immediately settled on the face of Jerzy Workisowa (47) and plunged its 0.5cm fangs into his right eyeball and started draining off the fluid.
As Jerzy screamed in agony, his two friends, Tadeusz Rose (35) and Sefton Delmer (49), sprang to his help but found themselves under a frantic attack from the threatened insect.
Tadeusz had his left eye torn from its sockets and left hanging down his cheek while Sefton suffered multiple puncture wounds to his left eyeball.
The butterfly was finally swatted into the corner of the tent by a flurry of furious fists where Sefton quickly squashed it with Jerzy's left hiking boot.
A mobile phone call to the emergency services saw an ambulance on the scene within minutes and all three men were rushed to Mlini's accident and emergency department where they were treated for serious eye trauma and shock.
Attacks from Southern Europe's vampire butterfly' are rare but, on average, 12 people a year are blinded after being attacked by this unusual insect.
Professor Judith Spencer, of St Andrews University's Entomology Department in Scotland, explained: "The Pieris rapae Linnaeus Maximus is a relation of the common cabbage butterfly but, at the height of its adulthood, has an unnatural and desperate craving for sulforaphane glucosinolate which induces a range of detoxifying enzymes.
"While this is found in cabbages, in particular in the veins of the outer leaves, it is much more in abundance in the human body.
"The insect can detect the scent of its chemical composition in humans and homes in on where the scent is strongest, and that tends to be where the skin is thinnest and the veins closest to the surface - the eyelids.
"The butterfly has particularly well developed fangs for piercing the most leathery of the outer cabbage leaves and so it is easy for it to inflict serious eye damage on a human."
Visitors to the Dubrovnik area have been warned by health officials to be aware of butterflies in their vicinity and to wear sunglasses whenever possible to thwart any attack.