By John F. Burns C.1996 N.Y. Times News Service BANBIRPUR, India - When the man-eating wolf came to this tranquil village toward dusk on an evening in mid-August, it was every child's worst nightmare come true.

The wolf pounced while Urmila Devi and three of her eight children were in a grassy clearing at the edge of the village, using the open ground for a toilet. The animal, about 100 pounds of coiled sinew and muscle, seized the smallest child, a 4-year-old boy named Anand Kumar, and carried him by the neck into the luxuriant stands of corn and elephant grass that stretch to a nearby riverbank.

When a police search party found the boy three days later, half a mile away, all that remained was his head. From the claw and tooth marks, pathologists confirmed he had been killed by a wolf - probably one of a pack that conservationists believe has been roaming this area, driven to killing small children by hunger or by something else that has upset the natural instinct of wolves to avoid humans, like thrill-seeking villagers stealing cubs from a lair.

It has been more than a century since India faced the threat of man-eating wolves on anything like the scale now terrorizing this region of the state of Uttar Pradesh. Since the first killing five months ago, 33 children have been carried off and killed by wolves, according to police figures, and 20 others have been seriously mauled, along this stretch of the Ganges River basin 350 miles from New Delhi. A hunt by thousands of villagers and police officers has killed only 10 wolves so far.

With new attacks each week, hysteria is sweeping the area of the killings, a terrain of lush fields interlaced with rivers and ravines that reaches about 60 miles north to south and about 40 miles across. More than 9 million people live in the region in some of the harshest poverty found in India.

A frenzy of rumors has put the blame for the killings not on wolves but on werewolves, the half-man, half-wolf creatures that have stalked their way through folklore for about as long as human societies have existed.

Other rumors have put the blame for the killings on infiltrators from Pakistan, who are said to have dressed up as wolves. Pakistan is India's traditional enemy.

Villagers have turned against strangers, and sometimes against one another, in lynchings that have killed at least 20 people and prompted the authorities to arrest 150 others.

``It's the worst wolf menace anywhere in the world in at least 100 years,'' said Ram Lakhan Singh, the animal conservationist chosen to lead an effort to kill wolves suspected of attacking humans.

The hunt involves thousands of villagers and police officers armed with bamboo staves and 12-gauge shotguns. But nobody can be sure that any of the wolves shot so far were part of the pack that Singh and other experts believe is responsible for the deaths.

Matters are still far from the disaster of 1878, when British officials in this area recorded 624 human killings by wolves. But fear is pervasive. Men stay awake all night, keeping vigil with antique rifles and staves. Mothers keep children from the fields, and infants are kept inside all day.

In the dark interiors of stark brick homes made clammy by the monsoons, fantastical stories are told, sweeping aside all attempts by officials to convince villagers that the killers have been wolves.

``It came across the grass on all four paws, like this,'' said Sita Devi, the 10-year-old sister of the boy killed by a wolf in Banbirpur on Aug. 16, as she moved forward in a crouch from a cluster of villagers gathered by a well. She told her story with tears in her eyes, to anxious murmurs from the crowd.

``As it grabbed Anand, it rose onto two legs until it was tall as a man,'' she said. ``Then it threw him over its shoulder. It was wearing a black coat, and a helmet and goggles.''

The girl's grandfather, Ram Lakhan Panday, who drove a truck in Calcutta for 50 years before retiring to his native village, said: ``As long as officials pressure us to say it was a wolf, we'll say it was a wolf. But we have seen this thing with our own eyes. It is not a wolf; it is a human being.''

Nearly half of India's 930 million people are illiterate, and the figure is higher in villages like Banbirpur. Many men head off to Bombay, Delhi and Calcutta in search of menial jobs, but living in slums among others much like themselves, they learn little to allay the superstitions of village life.

In the case of wolves, these are compounded by fairy tales told to children - Indian versions of "Little Red Riding Hood'' - in which wolves, and werewolves, are represented as among the most cunning and dangerous of all creatures.