When Jack and Man-Thing first encounter each other, Man-Thing reaches through a hedge to grab at Jack's shoulder, and Jack just grins and pats the hand fondly, clearly happy to see that his old friend is unharmed. Jack also mentions that Man-Thing has been captured numerous times and Jack has always been there to rescue him.
Jack and Elsa's relationship is sweet. While she is a bit aloof, they warm up to each other pretty quickly and agree to work together to free Man-Thing and get the Bloodstone. When he later transforms, she kills some of the hunters going after him, while he spares her life after recognizing her scent. In fact, the first thing Jack asks Ted once he's awake and human is if Elsa is okay.
Elsa could've just run away or killed Jack, but she fulfilled her end of the promise to help Jack get some sense of normalcy by placing a hand to his cheek.
Before he transforms into a werewolf, he begs Verussa that he doesn't want to kill anyone, even the monster hunters.
After he kills Verussa, Man-Thing leaves Elsa alone since she helped free him and instead leaves to find Jack. He's courteous enough to step over the corpse of a fallen hunter and even picks up one of the hunter's discarded ritual cloaks for Jack to wear upon waking on his way out.
Also, Elsa is smiling when she sees Man-Thing, which is the first time she's ever smiled throughout the entire special. She's actually relieved to see a monster, a friend, come to save her.
At the end of the film, despite everything that's happened to Jack forced into his werewolf form early and Ted nearly killed by the monster hunters, we see the pair have successfully escaped and have set up a campsite. Man-Thing hands Jack a cup of coffee and the two sit there and talk before deciding to go get sushi. Judging by how natural Jack's reaction to all of this is, Man-Thing figured out where Jack went off to, prepared camp with coffee and got everything just how his friend would like it after a night of werewolfing.
