There's the Viking(?) saga/story about the one ring ... oh, that's been done.
Um, the wolf at the door of the witch's hut, who everyone in the village called grandma ... oh, there've been a few of them.
How about a new version of battles between gods? Ah, right. Lots of them around at the moment.
How about Sisyphus? That river of fire thing hasn't been seen for a while. Maybe combine that story with Meganira, who turned her son into a water-newt for being rude?
How about a story more closely entwined with the original puss in boots lesson? Although, there do seem to be a few talking critters in stories already.
On a more serious note, the go-to place for these stories is Gutenberg. Using various search terms as myth, mythology, mythologi, etc. can lead to many, many stories - and well out of copyright. Looking for the shape of the stories as they were (justice, greed, humility, jealousy, etc.) and how the 'gifts' were bestowed may lead you into into the labyrinth, and through to the perfect fit.
…. And then there is of course that big wooden horse nobody actually ordered, which was delivered and dumped at the Trojan doorstep by some deliver person who worked for the Ancient Greek version of Amazon.
Best ignore me.
I think there's a Swiss myth / legend but I can't fully remember. I'll do some googling. But we have some wonderful folklore.
Pandora's box was where my head was at when I opened this thread (and it may well stay there).
Can you think of any mythical stories where the gift was, at least superficially, a boon but the recipient explicitly didn't want it in the moment of the giving (rather than not wanting it with hindsight)? Something along the lines of chosen one rejects the choosing.
It doesn't seem so funny in print but here you go:-
Paddy found himself marooned on a desert island and came across an old lamp so he rubbed the sand off it and POOF a genie appeared in front of him.
'I'm the Genie of the lamp it said and I grant you three wishes."
'To be sure,' said the Genie in his best Irish accent.
'Well then,' said Paddy 'I'll be having a bottle of nice cool Guinness if you please.'
The Genie waved his hands in the air and said a few magic words and POOF a bottle of the cool black stuff appeared from nowhere.
Paddy downed most of it in three giant gulps then sat back and belched.
As he watched, the bottle filled itself up until it was once again full to the brim.
'Bejesus.' said Paddy. 'Did you see that? It filled itself back up, just like that.'
'Yes,' said the Geni. 'It does that.'
'And I have two more wishes?' asked Patrick.
'To be sure you do,' said the Geni, entering into the spirit of things.
Paddy thought for a moment then held his bottle of Guinness in the air. 'In that case, I'll be having two more of these, if you please.'