Shakespeare had a nice line about nothing being more like a serpant's tooth, like an ungrateful child. :-)
(King Lear)
Oh, so you're the one who started the abuse of Shakespeare. Keep it up, and you'll go blind. And take another look at your sentence -- do you insist on shanghaiing Shakespeare on your linguistic misadventures, or are you willing to take responsibility for your own poor English?
"ungrateful adj. without gratitude."
"gratitude n. a feeling of appreciation for a kindness or favor received."
New Webster's Dictionary and Thesaurus of the English Language (Danbury, CT: Lexicon, 1992).
In the absence of a prior kindness or favor, one cannot honestly call anyone "ungrateful."