Helen asks Nadja for "eye of newt." The origin as an ingredient for witches' brew is from William Shakespeare's "Macbeth." The witches' scene describes a concoction that consists of "Fillet of a fenny snake, In the cauldron boil and bake; Eye of newt and toe of frog, Wool of bat and tongue of dog, Adder's fork and blind-worm's sting, Lizard's leg and owlet's wing, For a charm of powerful trouble, Like a hell-broth boil and bubble." Luckily, these terms refer to plants, not actual animal parts. Eye of newt is a pseudonym for mustard seed.
In the pre-credits scene with Laszlo and Guillermo, around the 44 second mark you can see a vintage Star Wars action figure of the droid 8D8 behind Laszlo. Matt Berry voiced this droid in The Book of Boba Fett and Berry wanted to include this in season 4, but wasn't allowed to as it would have been a spoiler at that point.