Being fond of poetry featuring imaginative insults I thought to make a copy of of a poem know as "The Flyting of Dunbar and Kennedy" to spice up my poetry season. Then I found that the version in the Penguin Scottish Verse gives only William Dunbar's side of the slanging match. Also I realised it's not an easy read on account of the antiquated and very Scottish vocabulary. Furthermore it's a little too long for this blog.
It can be found on the internet if anyone's enthusiastic enough. And someone has englished up part of it here.
Rather than act as ringmaster for the the big guns of verbal duelling, I've settled for a more manageable, one-sided example.
I'm also partial to alliteration, so double points to this gent.

SATYR UPON SIR NIEL LAING
(Sir Thomas Maitland)

Canker'd, cursed creature, crabbed corbit kittle,
Buntin-ars'd, beugle back'd, bodied like a beetle;
Sarie shitten, shell-padock, illshapen shit,
Kid-bearded gennet, all alike great;
Fiddle-douped, flindrikin, fart of a man,
Wa worth the, wanshapen wran.

Sir Niel Laing was a Catholic priest, a "Pope's Knight". So the title doesn't indicate knighthood but, I believe, an uneducated cleric. An educated priest would be styled "Master".
Sir Thomas was a genuine knight, and a religious reformer. Intriguingly he died(1572) en route to Rome in the company of a Jesuit priest. Second thoughts?
I think the same gent was responsible for two other poems which I like, but am unable to locate at the moment; approximate titles "The Pleasures of the Football", and "Anent the Thieves of Liddesdaill".

Glossary-
buntin-ars'd, fat-arsed
beugle-back'd, bent-backed
flindrikin, contemptible person
shell-paddock, tortoise
sarie-shitten, constipated?
Wa worth the(e), loosely, "you're not up to much.

Addendum, 3rd January: of the other poems I mentioned the correct title of the second is "Aganis the Thievis of Liddisdale", and was the work of Sir Richard Maitland of Lethington, father of Sir Thomas. I suspect that Sir Richard was also the author of the football poem, but am still in pursuit.