The fairy tale "The Selfish Giant" by Oscar Wilde has a lot of figurative language and figures of speech as it often occurs in this genre.
When the giant repeatedly says "My own garden is my own garden", is an example of anaphora, which is the repetition of a phrase or word for a specific purpose. Sure he does not use it throughout the story, but the phrase is repeated.
In the description of the garden you find many similes such as flowers like stars, and other comparisons.
Personification is also found as Spring and the seasons, the birds, and many things of nature decidedly stopped being in the Selfish Giant's garden because of the lack of children and "forgot" that garden altogether.
You could say there is synecdoche in the phrase "children are the most beautiful flowers of them all", which arguably is also a personification, and there is a lot of metaphors in both the meaning of the selfish giant (representing opression, overpower), and the redemption by the child who kissed him and took him to Paradise. The white blossoms are also representative of purity.
Hope this helps a bit.