- The Christmas episode. Specifically, the scene where Brain reads Pinky's letter.
''"Dear Santa, hello, hah hah, narf! This year Santa, I ask for nothing, but I wish to tell you about my dear friend, the Brain. He is honest and very hard working, and only wants what's best for the world, but he gets no reward. He is only greeted with defeat. He never gives up, but I know it must be very hard, so please, take anything that you have for me and give it to my best friend in the whole world, the Brain. Love Pinky. (PS. By any chance do you have in that big old bag of yours the world?)"
- The Halloween episode.
- Really, a lot of of Brain's abuse towards Pinky in earlier episodes can come across as a little cringe-worthy, like in the first episode when Brain grabs Pinky's ear and yanks on it forcefully, all while Pinky is clearly in pain. Their relationship became slightly less antagonistic as the show progressed, however.
- In "The Family That Poits Together, Narfs Together," we see Pinky watching a soap opera featuring a family reunion. He becomes increasingly emotional about it, and breaks down in tears, having not seen his family in several years, obviously missing them dearly. (Which makes it all the more sweet when he does eventually reunite with his parents later in the episode.)
- The ending of "Brain Acres" where Pinky and Brain have to bury Maurice, an anthropomorphic carrot Pinky becomes attached to. Pinky sings a sad song as they bury him and he finally starts crying.
- The song in question is a spoof of "Born Free", and surprisingly enough, it works.
- The ending to "Two Mice and a Baby". "Bye bye....Dada."
- Brain's flashback and Freudian Excuse from "Leggo My Ego".
- In "The World Can Wait", Brain finally finds love with a neighbor lab mouse, however just as he's finally won her over, she gets experimented on, leaving her traumatized and with a bigger IQ than his own, pressuring him to call off the romance until he has taken over the world before she does.
- Though whether or not it's actually canon is debatable, in The Nostalgia Critic's review of "The Purge," Rob Paulsen and Maurice Lamarche reprise their roles as their corresponding characters in an animated skit. Said skit features Pinky saying one of his typical non-sequitors, only for Brain to then suddenly launch into an absolutely brutal expletive-filled "The Reason You Suck" Speech towards Pinky, reducing the latter to tears. Seeing Brain call Pinky things like "you poisonous sack of disease" and literally wishing death upon him, all the while as Pinky sobs in absolute disbelief, is pretty hard to watch for some.
Brain: Goddamn it, Pinky, can't you get at least ONE fucking thing right? No, no, cut the music! Cut the music!Pinky: But-Brain: I have put up with this bullshit for too long!Pinky: (looking around uneasily) Bullshit?Brain: You are the syphilis to everything I've worked so hard for, you miserable, poisonous sack of disease!Pinky: But, Brain—Brain: Shut it, bitch!Pinky: Ah-! (gasps)Brain: I could have had the world years ago if you didn't keep... FUCKING IT up!Pinky: Oh, dear! I— (pulls on own ears nervously)Brain: Do me a favor and just... just die! Just die for the sake of all humanity!!Pinky: (bursts into tears) Oh Brain, I can't believe it!!Brain: Oh, yes, that's right! Cry! Oh, that's all you're good for, isn't it, you little shit!