So on the Sans page on The Undertale Wiki, when talking about the Grillby’s hangout, it only mentions that Sans “seemingly implies” Papyrus is getting tricked by an echo flower, when it is heavily implied that the flower is Flowey. I feel Flowey should at least be mentioned there in some way. I would do it myself but the Sans page is protected :P
Thanks for bringing it up! For some reason when I wrote that, I forgot to rephrase that sentence. I guess "He ambiguously implies that an Echo Flower or Flowey has been tricking Papyrus", might be better?