Several cats feature in the Revival of English Magic, but foremost among them is Bullfinch, Jeremy Johns's cat. It appears this sagacious creature is perfectly able to move between worlds, for even after Mr Strange's London house vanishes (after his departure into the Eternal Darkness), Bullfinch is able to visit it at will: "In London the only creature in the world who could still find the house in Soho-square was Jeremy Johns' cat, Bullfinch. Indeed, Bullfinch did not appear to be aware that the house was in any way changed and he continued to go there whenever he wished, slipping between number 30 and number 32, and everyone who saw him do it agreed that it was the oddest sight in the world".
It may be that this comfortable ease in the face of magic is something that all cats share. We are told that the cats of Venice are so far from being disturbed by the arrival of the awful Pillar of Darkness in their city that they at once flock to the parish where it is to be found.
We are also told that Jack Starhouse's affinity with cats is one of the things that made his fellow servants uncomfortable around him and made his master, Mr Tubbs, suspect that Starhouse was a fairy. When Starhouse spoke to cats, they looked at him "with an expression of faint surprize" on their faces, and he could encourage them perform "wild dances". 
Servants seem particularly attached to cats. Not only has Jeremy Johns a cat but so has Mr Norrell's manservant Lucas, and he is careful to carry it to safety with him when he and his fellow servants flee Hurtfew Abbey after it has been enveloped in the Eternal Darkness. His master however has a horror of these harmless and useful animals. "He hates cats even more than mice", according to Jonathan Strange; it appears Mr Norrell is one of those unfortunates who, should they find themselves in a room with a cat are "sure to be all over red pimples in an hour ".
Sir Walter Pole's valet also has a cat it seems, for on first viewing Sir Thomas Lawrence's portrait of Strange and Norrell Sir Walter is struck by the similarity of the expression in Mr Norrell's eyes to that of his valet's pet. (It seems they are both "a mixture of fearfulness and arrogance").
Strange's own sentiments towards cats are harder to judge. When he first arrives to court Miss Woodhope she is seated in the parlour of the rectory of S___ with her friend, Mrs Redmond, and playing with Mrs Redmond's black cat. Though Strange is warmly appreciative of this "tranquil domestic scene" he finds he "does not want Mrs Redmond and is undecided about the cat". This perhaps suggests an ambivalence towards the animals. Moreover it later emerges he has previously been responsible for some unknown act which once "frightened a cat belonging to the Master of Corpus Christi" - though this was in his heedless youth, when he was an undergraduate. In his maturity he appears to adopt a more sympathetic attitude, as shown by his tenderness towards the mother cat so unfortunately trapped in the bombardment at Quatre Bras.
Christopher Drawlight's behaviour towards Lady Bessborough's cat is of a piece with the general depravity of his character. Fearing the animal might shed some of its fur onto his spruce black clothes, he threw it from a third storey window:"...the cat survived, but one of its legs was never quite right afterwards and it always evinced the greatest dislike to gentlemen in black clothes.".
The greatest passion for cats of anyone in the book however is undoubtedly that shewn by Mrs Delgado in Venice. In her madness this lady lives among some fifty cats, her dearest and only companions, with whom she generally converses in their own language. In time, when Strange grants her her heart's desire, Mrs. Delgado happily sheds her human form and becomes a cat.