The 'Broken Terrarium' from the halloween events in DST is a reference to the Bluff Briar

[Meat Man (Alfons)]

Took me a while to catch, but there's a halloween event item in Don't Starve Together that is a broken terrarium with a plant inside, this is the Bluff Briar from Oxygen Not Included. The glass of it is broken so air has seeped into it, but bluff briars live in oxygen which we presume the DS world is also composed of, making it non stifled

There's also the 'Candy lice' (another halloween event item) thats a reference to the Meal lice, still as ugly looking as always.

You'd expect there to be even more references between Klei's games, but its these subtle things that makes it.