The British-English phrase I hope your rabbit dies, also I hope your rabbits die, may your rabbits die, etc., is a malediction, typically uttered as a parting shot after a quarrel.
As in the case of the good-luck incantation (white) rabbit(s), the reason the word rabbit was chosen is unknown.
The text containing the earliest occurrence that I have found of I hope your rabbit dies indicates that this phrase originated as one child’s threat to another—this text is the column Out of Doors, by William North, published in The Weekly Telegraph (Sheffield, Yorkshire, England) of Saturday 26th October 1918:
“I say it is.” “Well, I say it isn’t.” “You’re a story.” “No, I’m not. You are.” “I shall tell mother.” “Well, I don’t care. I hope your rabbit dies.” That, in the limpid language of the little ones, is pretty well how most really earnest, would-be helpful newspaper controversies are carried on. They begin all right, but are subject to the laws of degeneration.
The text containing the second-earliest occurrence of the phrase that I have found indicates that I hope your rabbit dies was already hackneyed—this text is the review of The Whirl of To-day, a revue presented at the Hippodrome, Leeds, published in The Yorkshire Evening Post (Leeds, Yorkshire, England) of Tuesday 24th February 1920:
Many comedians have drawn on enlistment and army experiences for patter, but Jack Edge, as principal comedian, contrives to find new material at the same source. The retort, “Then I hope your rabbit dies,” has, however, been overworked in pantomime and should be permitted to share the rabbit’s fate.
The other early occurrences of the phrase that I have found are as follows, in chronological order:
1-: From the column What we should like to know?, published in the Beeston Gazette and Echo (Beeston, Nottinghamshire, England):
1.1-: Of Saturday 3rd July 1920:
Who borrows the “Echo” to see if she has been jotted?
Does she try to buy one when she is referred to?
The name of the young lady who asserts she can swim with the aid of water-wings?
If she is possessed of fairy-like proclivities?
If webbed feet would assist to a greater extent than wings?
Who went to bed with his cycle clips on?
If he said “It’s a good job I don’t wear spurs”?
Who, when cursing a friend said, “I hope your rabbits die”?
1.2-: Of Saturday 23rd April 1921:
What the colliers said to the railwaymen in the public-house last Saturday night?
Who said “I hope your rabbits die?”
2-: From The Holidays. Exodus From the Hartlepools, published in the Northern Daily Mail (Hartlepool, County Durham, England) of Monday 1st August 1921:
The enterprise of the railway companies in re-introducing excursions—not at the old figure, but, in some instances, at reasonable fares considering the prevailing high prices—was amply rewarded, and there was a great rush from the town during the week-end.
This morning the exodus was quite big, and the railway officials got through their work splendidly. Ticket collectors and porters were no doubt, worried a good deal by more or less absurd inquiries, but they got through their work with great patience, as did all the officials. One official got a bit exasperated, and turning to a young woman, who seemed to be bemoaning the departure of a train said, “and I hope your rabbits die for not listening.”
3-: From the column Gadflights, by ‘Gadfly’, published in the Daily Herald (London, England) of Tuesday 13th February 1923:
More ducal dope from Percy *
Showing up “Curse of Internationalism”
Northumberland, Alan Ian Percy, 8th Duke of, born 1880 and still going wrong, is at it again. […]
This is the considered opinion of Alan Ian Percy: “The Labour Party is working to-day under the combined influences of International Capital and the International Revolutionary Movement, to facilitate the aims of Germany and Russia to achieve the domination of the world.” Curse the fellow! He knows too much! May his rabbits die!
(* The British army officer Alan Ian Percy (1880-1930), 8th Duke of Northumberland, financed and directed The Patriot, a radical right-wing weekly newspaper.)
4-: From the end of the letter in which ‘the Tank’, Blackpool’s war relic, describes its unceremonious removal from the Promenade—letter published in the Fleetwood Chronicle (Fleetwood, Lancashire, England) of Friday 16th May 1924:
I broke a lot of their new paving stones, and I’ll bet it cost a bit to shift me. I’m jolly glad, too, and I hope their rabbit dies as well.—Yours faithfully,
5-: From the column The Way of the World, published in the Daily Herald (London, England) pf Wednesday 3rd December 1924:
Litany After Lunch
May the rabbit die that belongs to the man who has hung his overcoat over my overcoat.
May the man break out in boils who has hung his overcoat over the overcoat that was hung over my overcoat.
May a thousand pitchforks jab the vitals of the man who has hung his overcoat over the overcoat that was hung over the overcoat that was hung over my overcoat.
May . . . [I move that we proceed to the next business.—Editor]
6-: From the column We see by the Papers—With a Few Irrelevant Comments, by A. P. Garland, published in The Sphere (London, England) of Saturday 6th November 1926:
THE TAXI-MAN’S LAMENT
(Taxi-cabs “crawling” in search of fares are to be banned in London by order of the Home Office.)
So we’ll go no more a-crawling—
The Law has said “Beware”—
Where the London streets are calling
To snatch a wayside fare.
No more we’ll blithely strive to grab
The skirts of happy chance,
Life’s hue is now a dreary drab,
And banished is Romance.
Our flag is down. To Jix we cry
Our humble, heartfelt thanks,
The man that—may his rabbits die!—
Reduced us to the ranks.
7-: From Hastings Borough Bench, published in the Hastings and St. Leonards Observer (Hastings, Sussex, England) of Saturday 12th February 1927:
John Griffiths and Edward Salmon, young men, were summoned for alleged assault on a youth named Edward Buckeridge […]. Edward Buckeridge […] said that on February 6th, at 10.25 p.m., he saw the defendants in Castle-street. He was standing talking to a friend when they went past and said “Good-night.” His friend said “good-night,” to them. They then came back, and Salmon said: “Who are you being cheeky to?” He caught witness by the throat as if to hit him. Witness tried to push Salmon away, and then Griffiths came up and pulled him away. They all then shook hands, but Griffiths said to witness: “Who are you turning your nose up at?” and hit him across the face with the back of his hand. At the same time Salmon punched his friend in the face. In answer to Salmon Buckeridge admitted that his friend said: “Good night, and may your rabbits die!” It was just a saying, and there was nothing in it.
8-: From The Sporting Times (London, England) of Saturday 12th February 1927:
Things People Say:—
(1) I hope your rabbits die!
(2) It’s the best car on the market!
(3) Pass down the car, please!
(4) We have only hospital matches!
(5) Would you mind collecting the tray from the lady at the end of the row!
9-: From John Bull Replies, published in John Bull (London, England) of Saturday 2nd July 1927:
T. B. (Aylesbury).—“I know my neighbour harbours hard thoughts about me and I don’t know what to do about it.” If you really want to be ruthless you can hope his rabbits die.