Green’s Dictionary of Slang

scutter n.¹

an unpleasant person, a general term of abuse.

1922		Joyce Ulysses 5: Scutter, he cried thickly.
1970		Current Sl. V:3 11: Scutter, n. One who gossips.
1996		(ref. to 1963) D. Healy Bend for Home 177: The cat had a bird in his mouth, the scutter.

In derivatives

scuttering (adj.)

unpleasant.

2001

P. McCabe Emerald Germs of Ireland 301: Scuttering tubs of guts who have to have it all their own way.