Mon Mome won last year's race at odds of 100-1
The last three Aintree Grand national winners - Mon Mome, Comply Or Die and Silver Birch are among the 112 entries for this year's race on 10 April.
The Venetia Williams-trained Mon Mome is bidding to be the first horse since Red Rum to record back to back wins.
Also entered are My Will, who was third in 2009, and leading challengers State Of Play, Cerium and Big Fella Thanks.
The 2006 Cheltenham Gold Cup winner War of Attrition, who is on the comeback trail after injury, is also included.
Comply Or Die is one of nine entries for trainer David Pipe along with the likes of Madison Du Berlais and Seven Is My Number, while Silver Birch's Irish handler Gordon Elliott is also planning to run Backstage.
As well as My Will, champion trainer Paul Nicholls has also engaged Taranis, the winner of last Saturday's Argentis Chase at Cheltenham and the current antepost favourite Tricky Trickster.
With two victories in the race (Earth Summit in 1998 and Bindaree in 2002) Nigel Twiston-Davies is the most successful current trainer and among his seven are Irish Raptor, Ollie Magern, Beat The Boys and Hello Bud.
As well as War Of Attrition and Silver Birch, the 38-strong Irish-trained entry also includes Vic Venturi, Black Apalachi and Notre Pere and 10 from the Willie Mullins stable.
Phil Smith, the British Horseracing Authority's head of handicapping, said: "There is fantastic strength in depth to the entries.
"There are more horses rated 140 or above among the entries in this year's race than in the previous 11 years that I have handicapped the contest."
Julian Thick, managing director at Aintree, added: "It is a measure of the race's health and stature as the world's most famous steeplechase that we have so many Grade One winners in there, including a Cheltenham Gold Cup victor.
"It will be interesting to see how Phil Smith frames the weights and we now look forward to the official unveiling of them at the Grand National launch on Tuesday, 16 February."