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In a fanfic called "Rock and Roll Equestrian Style", after Twilight Sparkle receives and invitation to Canterlot's Battle of the Bands from Princess Celestia, her stomach growls. Spike makes a remark that this reminds him of the events from The Ticket Master.
This happens to Twilight yet again twice in the first chapter of "Dashes, Dots and Pegasus Spots".
In a series of fan arts by a particular DeviantArt user, this happens to Princess Celestia due to her increased size, which caused her appetite to increase along with it. (According to this user, she apparently has more than one stomach.)
There also exists a fanart showing this happening to Trixie as well as one where this happens to Vinyl Scratch.
In the fanfic, "Rainbow Pie in the Eye", this happens a number of times. The first time, it happens to Pinkie Pie, and then it happens to Rarity twice. Applejack thinks she hears Rarity's stomach growl a third time, but it was actually something else...