"Where There's A Will" Achievement - What is this in reference to? Whose backpack is this?

[HighSpecGorilla]

Found a backpack behind the lost page in Ch. 12. Got an achievement and a voice line from Iris saying: "Whomever had this backpack must've been a real penny pincher" Seems like an easter egg but I think i might've missed something.

Anyone know what this is referencing to?

Is it the guy from the lost page?

[Morphic]

I think it is a crossover with the studio's other game 'Moonlighter'. So, presumably, the backpack is from the main character of that game since, in Moonlighter, you delve dungeons for stuff.

[ShandoKhan]

It is an easteregg for Moonlighter, the protagonist there is named will and he always carries a big bagpack, as you gather loot in dungeons, to later sell it and that need to fit in into the bag.
Theres the penny pincher line from: You throw away less valueable stuff, to fit in more valueable stuff.

[DigitalMallen]

It's a Moonlighter Easter Egg indeed!