PoisonBat

PoisonBat is the het ship between Bruce Wayne and Pamela Isley from the DC Comics fandom.

Fear State
After being experimented on by Jonathan Crane, Bruce goes to Ghost-Maker for his assistance in making sure nothing had been planted in his brain. Bruce had developed a helmet with Cyborg that now would allow Ghost-Maker to access his memories and make sure nothing had been tampered with and after activating the device, Minhkhoa jokingly first looks into what he calls the dirty stuff and a memory is shown of Ivy and Batman kissing. It's one of three separate memories shown, with Talia al Ghul and Selina Kyle being the other two, with the fact that Ivy was that significant enough to him for her to be featured alongside two of his undoubtedly most significant love interests, suggesting Ivy and Bruce had been closer than thought previously.

Poison Ivy
In the thirteenth issue of her solo comic series, Ivy returns to Gotham after her road trip with Janet. Bruce confronts her in Robinson Park, and after a brief fight between them, Bruce warns her not to cause any trouble or else he will be forced to respond, saying that they hadn't always been enemies and were once something else, a clear reference to their past relationship. Ivy hallucinates Batman earlier in the series when she is about to confront Jason Woodrue, with it being the words of the imaginary Batman that gives Pamela the motivation to finally stop Woodrue for good and kill him.

Injustice 2
In Ivy's ladder ending, after killing Braniac and slaughtering Earth's heroes, it can be visibly shown that in the aftermath of conquering the planet Ivy has spared both Bruce and Harley Quinn. This is very likely due to both Harley and Bruce being prominent romantic interests of Ivy thus her wanting to keep them both alive due to her attachment of each of them.

Poison Ivy: Cast Shadows
Bruce and Pamela are forced to team up after a Poison Ivy copycat killer begins terrorising Arkham, Bruce is subsequently poisoned and needs to kiss Ivy for the cure. Bruce confronts Ivy, and debates knocking her out to make sure she doesn't kill him after he would pass out after receiving the cure. In the end, Bruce hesitates and simply just kisses her, putting his faith in Pamela. Gotham Tower begins to collapse afterwards and Bruce is nearly killed. Ivy and Bruce admire her plant creations together and Bruce compliments her on the talent she possesses. After returning to her cell once the killer had been caught, Ivy complains about the lack of light she receives in her confinement which Bruce hears. The next day, Ivy awakes to find that an anonymous benefactor has payed for Ivy to be transferred to a deluxe cell, with a room that's filled with flowers and sunlight. Ivy looks up to the sky smiling and thanks Batman.

Fanon
PoisonBat is a small ship in the DC fandom, due to both characters having far more famous ships that easily overshadow it. Some naturally find the hero/villain dynamic interesting, especially with Ivy being one of the most dangerous villains Bruce knows thus creating an interesting power dynamic between the two. Some think Ivy could make an appearance in the Robert Pattinson Batman films, due to how Riddler flooding the city was bound to have killed many of the plant life that inhabited the city in the first film, not to mention some thought Riddler's character borrowed some of Ivy's traits, such as her hatred of the rich corrupts that pollute Gotham.
 * FAN FICTION