Moses, the tame raven, preaches about Sugarcandy Mountain beyond the clouds. Sugarcandy Mountain is like a placed called Heaven. Moses claims that animals go to Sugarcandy Mountain when they die. In Sugarcandy Mountain all is well. Clover grows all year. In Sugarcandy Mountain, it is Sunday seven days a week. Also, lump sugar and linseed cake grows on the hedges in Sugarcandy Mountain.
In Animal Farm, Sugarcandy Mountain represents peace beyond this world. All animals go there if they work hard. Moses shares his beliefs as he represents organized religion in the book. The pigs allow Moses to share his tale because it will sooth the animals and prevent uprisings:
He is tolerated by the pigs because he takes the animals' minds off their troubles by preaching to them about a happy land called the Sugarcandy Mountain.
This question has already been asked and answered on eNotes. Here is a link for you: http://www.enotes.com/animal-farm/q-and-a/what-sugarcandy-mountain-150779