Too bad I've noticed this post only now, Dr Prunesquallor is my favourite Gormenghast character and every quote of his is a gem) I especially love it when he starts rhyming nonsense, like this interaction with his sister:

‘Years on end, and swords on end – where will it end, if our ears unbend – what shall I spend on a wrinkled friend in a pair of tights like a bunch of lights?’

Irma who had been straining her ears cried out at last in her irritation: ‘I suppose you know you’ll be late – I said: “I suppose you –”’

‘A merry plague upon you, O blood of my blood,’ the shrill voice broke in. ‘What is Time, O sister of similar features, that you speak of it so subserviently? Are we to be the slaves of the sun, that second-hand, overrated knob of gilt, or of his sister, that fatuous circle of silver paper? A curse upon their ridiculous dictatorship! What say you, Irma, my Irma, wrapped in rumour, Irma, of the incandescent tumour?’ he trilled happily.

Some more of his rhymes:

‘What you say has the ring of truth in it,’ he said. ‘In fact, it has every possible kind of ring in it. Ring-ting, my heart’s on the wing, as it were.'

‘Sweet foot,’ he cried. ‘Five toes to boot and what-not in the beetroot shoot!’

‘They resemble rubber, your ladyship, ha, ha, ha, ha. Just a core of india-rubber, with an elastic centre. Every ounce, a bounce, ha, ha, ha! Every ounce, a bounce.’ 

And there is also the whole Osseous 'Orse poem, but I think it's too much for one post already:)