According to the Pipis (Item) page on the Deltarune Wiki, you can obtain a Pipis in a secret cutscene if you do not have the Dealmaker/Puppetscarf equipped.
However, despite unequipping the Dealmaker before entering that room, the cutscene still featured Spamton, and did not provide the Pipis (Item), this means that simply owning either of the items triggers the cutscene.
Since these items cannot be sold, a save file that has beaten Spamton NEO and claimed his reward cannot also acquire the Pipis item, which is unfortunate.
Anyways, I made this post to ask for an edit to that page to clarify this detail, I'm not sure if I'd be allowed to do it myself