In times long gone, when youth was more polite, everything was cheaper, and girls were more eager, sorcerers could breathe life into inanimate matter and create stone servants this way. Gargoyles - for I have them in mind - can be found in ancient cities to this day, but their magic has vanished and now they are nothing more than cornice decorations. There are, however, exceptions such as the Loc Muinne gargoyles - still enchanted and still dangerous.
Theoreticians of magic still argue about classifying gargoyles. I favor the school claiming they are a type of golem. For gargoyles are nothing more than fancy sculptures animated with magic and programmed to do simple tasks. They can complete only the most rudimentary works, so they are most often guarding a territory, even if their creator turned to dust long ago.
The gargoyle is a magical creature and often has surprising tricks at it's sleeve. Teleportation for example: an opponent makes a blow, and the gargoyle disappears only to emerge elsewhere at the same moment. Like behind it's enemy. It's even worse when the gargoyle appears over his opponent - then it just falls down and crushes it's victim beneath the weight of it's stone body. Thanks to their medallions, witchers can perceive disturbances in magical aura, so they see the point where the gargoyle will appear moments before it materializes, so they have time to react. However ordinary people tend to die crushed.
Fighting the gargoyle means fighting solid rock, so it should not be surprising that poisons are useless, as are fire and oils causing bleeding. Because of its great mass, the gargoyle's stone body cannot be unbalanced, let alone knocked down. Immobilizing one with a trap will fail, as gargoyles can teleport and will flee snares using this ability. They have no weaknesses at all.