Fearsome "XL Bully" cats are up for sale on the internet.

Menacing 'XL Bully' cats are up for sale on the internet (c) Instagram

Menacing 'XL Bully' cats are up for sale on the internet (c) Instagram

Animal welfare groups are concerned that the felines - a cross between the Bald and Dwarf breeds - could become the latest pet trend.

Pictures of the "XL Bully" cats, which were first bred in the US, have been shared on social media and have even led some users to question if they are real due to their menacing appearance.

Campaigners are alarmed by the dubious breeding practices and fear that the lack of fur could cause skin diseases.

Cats Protection's Head of Clinical Services Alison Richards said: "Our veterinary assessments of the photos and videos we have seen of these cats have raised serious welfare concerns."

A spokesperson for the RSPCA added: "We would also urge breeders to prioritise the health and welfare of any animal over the way they look."