"Charlie the Human" is the 29th episode of All Dogs Go to Heaven: The Series.
Having discovered things that humans can do that dogs can't, which interests him, such as using money and going into actual restaurants, Charlie wishes to become human. Meanwhile, Annabelle assigns him and Itchy to return some notes to an absent-minded scientist named Dr. Higgenbotham, and gives them the miracle dog tag. Of course, she gives it not to Charlie as before, but to Itchy this time because the latter knows they're only for emergencies. Charlie later convinces Itchy to give him the tag anyway, so he uses it to turn into a human being.
Especially according to the final episode "He Barked, She Barked," this is the third time Charlie misuses the Miracle Dog Tag, counting "Heaventh Inning Stretch" and "Charlie's Cat-Astrophe."