It would maybe go like this: Damian is having a bit of trouble taking care of Goliath and nowhere in his unusual and extensive curriculum was he taught how to take care of baby dragon bat. Naturally he does some research and comes across Rubeus Hagrid, who by now has made a good reputation for himself as expert on all things magical creatures.

He convinces Bruce to take them to England for a few weeks and sneaks away to corner Hagrid outside of a bar, demanding to be taught about the proper care of dragon bats.

Hagrid is immediately charmed by the open care and love Damian has for all animals, not just the ones that fit a certain standard (it also doesn’t help that Damian reminds him painfully of a younger Harry with his sharp green eyes and thirst for knowledge. Hagrid did not stand a chance)

He takes Damian back to his cottage, watching as the hard shell Damian has built around himself immediately fades away when he meets Fang. They immediately take to each other, the old dog looking more lively than he’s been in years as Damian starts ranting about his own dog Titus and his array of other pets while Hagrid makes them some tea.

They sit down and Damian takes a sip of his tea, immediately spits it back out and becomes the first person ever to have the heart to inform Hagrid that his food sucks. Instead of being offended, Hagrid laughs so hard he starts crying because all the faces people were making while eating his food suddenly make sense and he can’t believe in all these years nobody has bothered to tell him! They strike an agreement that Hagrid shows and teaches Damian about all the magical creatures he knows and in exchange, Damian teaches him how to improve his cooking so that it becomes halfway edible.

Damian makes then a new batch of tea, listening intently while Hagrid takes over the talking and tells him all about the development stages of dragon bats, even offering to house Goliath if things get out of hand, and offers to buy some supplies from Diagon alley for him that Goliath would like. (For the sake of simplicity: the statue of secrecy has been long lifted and British wizards live freely amongst the population). Damian has never been so impressed in his life when Hagrid mentions the giant three headed dog he calls Fluffy and suggests to set up a play date with Goliath and Fluffy when Goliath is old enough to fly.

When Damian sneaks back to their hotel room to a pissed off Bruce, he explains where he’s been manages to only get two weeks no patrol as punishment (Bruce is barely holding himself together from aweing out loud) and insists that Bruce come with him to Hagrid’s the next day.

Bonus:

Hagrid immediately recognises Bruce (despite not recognising Damian) and Bruce is panicking thinking their identities are busted (cause how can he explain to the media how Bruce Wayne’s son come in possession of a dragon bat??). Father and son then proceed to be utterly gobsmacked when Hagrid goes “yer pennyworths kid aren’t ya!” And explains how he’s recognised Bruce from a photograph Professor McGonagall showed him of her old military friend who writes to her every now and then.

Bonus 2: