!!The Books
* In the first book, Harold, when he knows Chester was starving the poor rabbit, manages to get Bunnicula out of his cage, and carries him to the big bowl of salad on the table.
** Much later, Harold sings a lullaby to the titular bunny in "dialect of the Carpathian Mountain region", which cemented the friendship of himself and the vampire rabbit.
* In the graphic novel adaptation of the first book, when Harold (acting as the narrator) explains about Chester having joined the Monroe household a few years previous as a birthday present for Mr. Monroe, he states "In my opinion, he's never received a better gift." He also makes a point of saying that he's proud to call Chester his friend.
* A brief exchange between Harold and Chester in ''Nighty-Nightmare''. While definitely a StealthInsult on Chester's part, one does get the impression that [[VitriolicBestBuds he's being at least half-sincere]].
-->'''Harold''': The trouble with you, Chester, is that you've lost your capacity to enjoy the simple things in life.\\
'''Chester''': That isn't true. [[InsultOfEndearment I enjoy you.]]\\
'''Harold''': [[SincerityMode Thank you]].
* At the end of ''Return to Howliday Inn'', Chester rallies the animals to use ventriloquism to remind all the nursing home residents of their beloved pets, which persuades Sunnydale to make Hamlet the official pet of the home, saving him from being put to sleep.
* "For god's sake, Harold, use your brain, such as it is. Can't you see that he's ''scared?''" - said by Chester while he comforts a frightened Bunnicula in ''Bunnicula Strikes Again!''
** Made all the more heartwarming by the fact that Chester was at one point absolutely convinced that he had to ''kill'' Bunnicula in order to protect the rest of the world. Although Bunnicula is more or less confirmed as a vampire at this point, he's also proven effectively harmless, so Chester seems to have finally picked up on that and is doing what he can to make amends. After nearly 6 books of him being convinced of Bunnicula having nefarious intentions, this is almost catharsis for both fans and Bunnicula, who has lived with Chester for most of his life.
** Even more heartwarming is piled on because this (and Chester's subsequent peacemaking with Bunnicula) puts an end to Harold's worrying about change that has happened since Toby read ''[[Literature/SherlockHolmes The Final Problem]]''. Yes, things have drastically changed by the end of the book, but it's a good change, not a destructive one.
* Chester's bonding with Bunnicula at the end of the book. He makes a habit of sleeping next to Bunnicula's cage, and one night when Harold comes downstairs to sing Bunnicula his habitual lullaby... he happens upon Chester singing it instead. Aww!

* Chester is shown to be extremely upset when it seems like the Monroes might give Bunnicula away to M.T. Graves, and even calls him "our bunny" in ''Bunnicula Meets Edgar Allen Crow''.

!!The Cartoon
* Harold's kindness was enough to soothe the bloodlust from a viking ghost.
* Chester caring for [[spoiler: what he thought was]] Bunnicula's son, and even risking his own life to save him when he appears to be in danger.
* Even when affected by a ghost alligator's sadness in "Alligator Tears", Chester tells Harold [[PlatonicDeclarationOfLove how much he loves him like a brother]] and convinces him to come back home.
* "Spiderlamb": Chester is very accommodating to Harold when he comes home from the vet, even agreeing to read him a bedtime story. Further on, Chester's freaking out about the Spiderlamb is not because it's a supernatural creature and it's in his house; it's more because it might be a danger to Harold.
* In "Evil Cat Videos", Chester snaps out of his brainwashing when the mouse ghost orders him to scratch Mina and [[IntrinsicVow he can't bring himself to do it]].
* When the usually cheerful and optimistic Mina starts crying due to the Ghost Alligator spreading sadness inside the apartment in "Alligator Tears", Chester starts nuzzling her.
* In "Adopt a Vampire", Chester apologizes to Bunnicula and the two start to become closer. From this episode on, Chester seems to be much nicer to Bunnicula.
* The final episode "Oh Brother!" ends with Mina finally discovering Bunnicula's vampiric nature... and she's ecstatic about it!
** Also when Harold finds out Bunnicula has a brother, he considers him to be his brother as well. He keeps on calling him "brother" throughout the whole episode, even after he does one horrible thing after another.