Puppy Dog Eyes / Fan Works
Miyoko in when she asks Kyon to go see a movie together.
Kyon: Big Damn Hero In the sequel to the fic The Legend of Zelda: Twilight Princess , Rusl notes that "Shad's puppy-dog pout" was practically legendary.
Til the Sun Grows Cold and the Stars Grow Old Latias in is fond of using these to get out of trouble, usually after playing a prank on someone.
A New Chance at Life Several fanfics usually feature this as a minor genjutsu or ninjutsu.
Turnabout Storm Pinkie Pie after Phoenix Wright tells her that their investigation does not involve finding oatmeal, much to her dissapointment.
Apple Bloom uses them when begging Twilight to let her be her assistant in her investigation.
Kyle in the story "Alternate Ending" does this at the end to Lenny.
Shark Tale Erin in - she's the only main character to have For Good Brown Eyes, and she uses them to great effect with her brother and her not-boyfriend.
Sherlock Holmes in the , to the point where Mrs. Hudson suspects that neither his mother nor any other susceptible female with whom he'd come in contact had ever been able to resist those big Deliver Us From Evil Series Gray Eyes.
Calvin and Hobbes: The Series
"My client has eyes. [...] Yes, eyes. The innocent eyes of a puppy."
In the , not only does Apple Bloom apparently do this all the time with Applejack, but she's taught Spike how to do it too (he complains that it makes his eyes hurt).
Pony POV Series The Dashverse: Rarity does this in Hot Heads, Cold Hearts, and Nerves of Steel to convince Shining Armor to let her make modifications to his uniform. He caves immediately.
Rainbow Dash apparently did this to him all the time when she was a filly.
From the , we have Takato's secret weapon; the Tamers Forever Series U.P.D.E. " Ultimate Puppy Dog Eyes. TM (Now with more glimmering!)
Secret weapon? does that mean this should be in spoilers?
Diamond's pet kitty in the MLP fancomic learned this from Diamond and Dazzle the time he spent as a puppy. Has used them on Diamond and Spike to get cake and candy, respectively.
: In chapter 4, Asuka didn't want Akiko to keep a stuffed toy. So that Akiko used the puppy dog look on his father, and Shinji used it on Asuka. She relented.
HERZ Shinji found himself caught between the two most important females in his life. His gaze darted to and from his wife and daughter. He settled on playing the sad puppy dog to Asuka. Faced with two pleading looks, Asuka relented.
In , Applejack pulls them on Sunset when she's on the verge of refusing to help find The Witch of the Everfree the Great White Wolf.
Rarity pulls them too, trying to draw a story out of Sunset after she offhandedly mentions having met a griffon ambassador.