Count Bonalli has eyes that glow in the dark. He can see clearly in the dark but is extremely sensitive to light. He is highly charismatic. His significant others are: Peter the Hunchback, Ethel Matrol, Dave Brunting, Tandy, Big Harry and Professor Kew.

The character was created by Andrew Murray.

In 1920, Sexton Blake encountered a gang leader known as the Owl. This short, thick-set man — real name Count Bonalli — stood out among run-of-the-mill crooks for two reasons: his eyes! A medical condition had made him ultra-sensitive to light. This would have been a handicap to most people, but for a criminal, whose activities are best conducted in the shadows, it proved a distinct advantage — for the Owl could see perfectly well in absolute darkness.

A side effect of this condition caused the Owl's eyes to appear luminous in the dark. This struck fear into those who encountered him and helped him to maintain mastery over the gang he controlled. Together with his creative cunning, it made him a formidable opponent and a man that Sexton Blake and Scotland Yard were determined to capture.

Little is known about this crook's background beyond the fact that he hails from some continental state and has every right to the title he bears. He has a trick of vanishing for months on end, inexplicably disappearing from his haunts only to later reappear just as suddenly. His methods are peculiarly his own, and he usually works single-handed, though he later teams up with Professor Kew.

Chronology:

1. The Cargo Stealers (UNION JACK issue 863, 1920)
Sexton Blake is asked to investigate a series of robberies from cargo vessels along the Thames. He discovers that a gang is at work and disguises himself as one of their number. They are led by the Owl, who has created a cunning scheme whereby cargo is dropped to the riverbed and recovered by divers. Blake breaks up the gang but the Owl escapes.

2. The Jewel of Muralpoor (UNION JACK issue 877, 1920)
The Owl tricks Tinker and Hon. John Lawless (though he had intended Tinker and Sexton Blake) into attending a masked ball where he frames them for the theft of a maharajah's jewel. Sexton Blake quickly recognises that the Owl is responsible and gets on his track. Tinker is captured by the crook but Blake and Lawless — who has followed the Owl's henchman, Big Harry — arrive in time to rescue the youngster. The Owl evades capture, minus the jewel.

3. The Man in Smoked Glasses (UNION JACK issue 880, 1920)
Having kept a low profile for a while, the Owl tries to swindle £60,000 from a shipping company by impersonating the Greek millionaire who has come to London to sell three steamers. Sexton Blake and Tinker tussle with him, expose his scheme, and rescue the real tycoon. Bonalli escapes by the skin of his teeth when the taxi in which Blake is pursuing him breaks down.

4. Eyes in the Dark (UNION JACK issue 995, 1922)
Professor Kew impersonates a duke, steals his pearl and diamond necklaces, and has them stored in a hotel's strong-room after having been told all about the electrical security systems that protect it. He passes this information to Count Bonalli, who uses it to gain the valuables. Kew and the Owl then kidnap the real duke in order to make it appear that the man has for some reason stolen his own property. Sexton Blake and Hon. John Lawless get wind of the scheme and foil it. The loot is regained but the criminals get away.

5. The Temple of the Blind (UNION JACK issue 1,007, 1923)

6. The Secret of the Mine (UNION JACK issue 1,010, 1923)

7. The Gargoyle's Secret (UNION JACK issue 1,039, 1923)
Count Bonalli again teams up with Professor Kew to steal a shipment of valuable gems. They hide their loot in an abandoned church, but when they are followed to it by one of their victim's employees, a hired henchman kills the man, and Sexton Blake is brought in to investigate. With their hiding place exposed and the gems recovered, Kew and Bonalli have no choice but to abandon their scheme and flee.

8. The Sign of the Yellow Dragon (UNION JACK issue 1,063, 1924)

This marks the final appearance of the Owl.