In 2019, Tiger Roll emulated the legendary Red Rum by landing back-to-back Nationals at Aintree.
Victory again in the world’s richest Jumps race on Saturday, April 4 would earn the ten-year-old a place in the all-time record books.
It is far from certain he will even be there. Owner Michael O’Leary, of the Gigginstown House Stud, has expressed doubt if the horse is lumbered with a big weight, while an injury setback has also hampered preparations for the Gordon Elliott-trained star.
However, he is due to make his seasonal appearance at Navan next month or at the Cheltenham Festival in March, and Elliott is keen to go for the hat-trick bid.
What’s more, Tiger Roll is a clear 7/1 favourite for the £1 million race, which will again be sponsored by Randox Health.
And another Aintree triumph would cap the extraordinary career of a horse who has also won four times, and three different races, at the Cheltenham Festival.
A total of 105 horses have been entered for the National, and these will have been whittled down to a maximum of 40 come the big day.
Elliott accounts for 18 of the 45 Irish-trained possibles, the most of any handler, as he chases a fourth success in the race. If victorious, he would join Fred Rimell and Ginger McCain as the most successful trainers in National history.
Elliott's team also features leading Magners Cheltenham Gold Cup fancy Delta Work and the exciting novice Champagne Classic. Both horses are owned by Gigginstown House Stud.
Other Grade One performers among the entries are Cheltenham Gold Cup heroes Native River (Colin Tizzard) and Sizing John (Jessica Harrington, plus two-time Betfair Chase victor Bristol de Mai, one of seven contenders for dual National-winning trainer Nigel Twiston-Davies.
Irish Grand National victor Burrows Saint is one of ten entries for Willie Mullins, who landed the spoils in 2005 with Hedgehunter. The Mullins contingent also includes last year's impressive Randox Health Topham Chase victor Cadmium and recent Thyestes Chase scorer Total Recall.
Last year's runner-up Magic Of Light ( Harrington) and impressive Munster National heroine Cabaret Queen (Mullins) are the pick of four mares engaged. No mare has won the Grand National since Nickel Coin in 1951.
Tiger Roll is not the only previous National winner among the entries because also lining up is by One For Arthur (Lucinda Russell) who, in 2017, became only the second Scottish-trained scorer after Rubstic in 1979. Only four horses have regained the National -- Red Rum (1973, 1974, 1977), Manifesto (1897 and 1899), The Lamb (1868 and 1871) and Peter Simple (1849 and 1853).
Walk In The Mill (Robert Walford) has an excellent record over the National fences and fared best of the British-trained contenders in the 2019 race, finishing fourth. Walk In The Mill is a 20/1 chance with Betway, the National meeting's official betting partner.
The ten-year-old, who carries the colours of Baroness Dido Harding, captured the Grade Three Randox Health Becher Handicap Chase for the second time at Aintree in December, making him the first back-to-back winner of the race.
Trainer Walford said: "Walk In The Mill came out of the Becher in great form and the intention now is to run him over hurdles at Chepstow on Friday.
"This will probably be his last fun before the National. There are other races that we could run in, but I would like to go to Aintree with a fresh horse, so to run now suits our schedule.
"He has been a brilliant horse for me. He just seems to love those fences at Aintree and it is exciting to have a live National contender on our hands."
Sue Smith, who tasted National success in 2013 with Auroras Encore, has given Vintage Clouds an entry after his impressive victory in the Grade Two Peter Marsh Handicap Chase at Haydock Park on January 18. He is a 25/1 chance with Betway.
Vintage Clouds fell at the first in the 2019 National and was pulled up in the Becher Chase after a bad mistake. But his owner, Trevor Hemmings, is the joint most successful in National history with three wins -- Hedgehunter (2005), Ballabriggs (2011) and Many Clouds (2015).
Smith said: "He has slightly struggled over the Aintree fences, particularly in the Becher, but we want to keep all options on the table for the time being.
"He jumped superbly in the Peter Marsh and has come out of the race very well."
Hemmings also has Lake View Lad (Nick Alexander) and Warriors Tale (Paul Nicholls), winner of the 2018 Grand Sefton Handicap Chase over the National fences, engaged.
Champion trainer Nicholls ended his wait for National glory in 2012 with Neptune Collonges. The Somerset handler's six entries include Listed Badger Beers Silver Trophy victor Give Me A Copper, who is part-owned by former Manchester United manager Sir Alex Ferguson.
Other high-profile entries include the JP McManus-owned pair of Kimberlite Candy (Tom Lacey)and Ok Corral (Nicky Henderson), who have started 2020 with coveted handicap chase successes at Warwick and Doncaster respectively, plus Welsh National hero Potters Corner (Christian Williams), who is part-owned by Wales rugby union international Jonathan Davies.
French-trained entries are Balko Moriviere (Jerome Larrigade) and Disco d'Authie (David Cottin). The only French-trained winners of the National are Huntsman in 1862 and Cortolvin in 1867.
Weights for the great race will be unveiled before an invited audience at St George's Hall in Liverpool on Tuesday, February 11.
Betway's Alan Alger said: "Since crossing the line first in last year's race, the extraordinary Tiger Roll has been perched at the top of the betting for the 2020 renewal and we are currently offering a top price of 7/1. Could he be the first horse to win the race three years in a row?
"Native River, the 2018 Gold Cup Winner, looks to have been campaigned for a crack at the National and the Colin Tizzard-trained gelding is available at 20/1 with us.
"Despite winning almost all there is to win in horse racing, the National still eludes Nicky Henderson. This year, he has four horses entered in an attempt to break his duck and for the master trainer to win the race with any of his entrants is 10/1."