Sam the Skull is a fictional cat, said to roam around Glasgow, Scotland, most famously in the song with the same name. He is often also called The Glasgow Cat.
Sam the Skull is said to be a very tough cat, and in the song, written by Harry Hagan, he states that he has claws like a crocodile's jaw, and he often swallows both rats and occasional dogs. It is also told that the bars on the prisoner windows are not to keep prisoners inside, they are to keep out the Skull. However, the story is that the RSPCA came to catch him in a car, but he stole the car and drove away, and now resides with a bird, in a single end in Maryhill.
The song is most famously recorded by Alastair McDonald, for his album Scottish Lauglines, but it has been recorded a few times, for example by the Scottish band Gaberlunzie.
The song Tha Lugton Dug' (Scots for Lugton Dog), by Alastair McDonald, tells a story about a dog just as tough as Sam the Skull. The story ends, after the Dog tells about him eating vampire bats: