Centering around an underpass, the legend has two main variants, the commonality between them being the presence of a rat-like creature who appears in the pedestrian walkways at night.

The most commonly told story of the Ratman involves an old tramp who used the underpass to escape from the rain and the cold at nights. The story goes that he was old and barely able to walk. One night a group of teenagers beat him half to death and stole his blanket, the only real source of warmth he had. Dying from his injuries and the biting cold of the night, he succumbed to hypothermia - his stiffening corpse nibbled and gnawed on by the numerous vermin who inhabit the area.

Soon after, locals reported odd noises. Namely, high-pitched squealing and the sound of nails dragging along the walls. Whether evidence of a real ghost or an overactive imagination, the fact remains that this story and subsequent noises led to locals dubbing the creature the Ratman of Southend.

The other main version of the story is far more fanciful and seems to have emerged in schools, a tale passed between children to frighten and unnerve their classmates. The Ratman is no longer a ghost, but a real creature. The story runs that a Mayor of the town was a known adulterer and was eventually cursed for hisinfidelity - in the form of a grotesque child. A baby with the elongated snout and worm-like tail of a rat. The child grew and developed tastes for flesh.

The Mayor had the underpass constructed to conceal his monstrous child. And via hidden doors, the Ratman escapes at night, scaring off any visitors who disturb his rest.

Local author, Dee Gordon, detailed the local ghost stories of the Essex area - including that of the Ratman - in the book Haunted Southend.

Ghost tours in the Essex area have been known to include nighttime visits to the Ratman Tunnel in the hope of seeing the creature.