I was known as 'Skinny Lizzie' (character in the Beano comic, a member of Lord Snooty's gang) because I was skeletally thin, with knock knees and also bandy legs. I didn't mind though - nearly everyone had a nickname in those days.
Later I got called 'The Galloping Hairpin' when I started horse-riding.
But for most of my life I've been known as Paddy, due to being half-Irish. (No, I haven't got a temper!) There was a TV show in the 1960s called 'The Rag Trade', and Miriam Karlin played a shop steward called Paddy. I think that's where the idea came from.

I rather wish I was slender enough these days to warrant a skinny nickname.