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Ariana Grande is saying her goodbyes to Cat Valentine, the character she played for four years on Nickelodeon's "Victorious," and later, "Sam & Cat." 

The actress-turned-singer tweeted a letter to her fans, after the network announced the cancellation of "Sam & Cat" on Sunday.  Ariana says she will always hold Cat "near and dear to [her] heart," and will always appreciate the character's "sense of wonder" and ability to see "negative obstacles as opportunities to make things good." 

Ariana credits Cat for her "personal growth from teenager to adult," and admits that while she hid behind the ditzy high-schooler for years, she is now able to show the world who Ariana is.  

You can read the entire letter in the link below:

Ariana's letter is also sparking controversy for leaving out one important thank-you.  The singer failed to mention her co-star Jennette McCurdy, fueling rumors that a contract dispute between the two caused the show to end. 

Earlier this year, Jennette blasted the network on Twitter after boycotting its Kids' Choice Awards and was also caught up in a nude photo scandal.  The fate of the show had been on the rocks since then.  "Sam & Cat's" finale episode airs on Thursday.  

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