spawny, adj. — Green’s Dictionary of Slang

spawny adj.

[ety. unknown. ? link to Scot. game spawnie, played with buttons, in which one player throws a button, the others attempt to throw theirs nearest to it, and the button that comes within a spawn (SE span) is the winner]

lucky.

1993		I. Welsh Trainspotting 96: Spawny bastard! You spawny fuckin cunt Renton.
2012		(con. 1980s) I. Welsh Skagboys 274: Ye wir up her aw night, ya spawny cunt.
2018		I. Welsh Dead Man’s Trousers [245]: spawny bastards [...] lucky cunts.