Thinking 'bout Sergei the Snail from Phineas and Ferb and how Doofenshmirtz recognised him immediately, which suggests he's been sent to deal with Heinz before, and how the usual hatless Perry = platypus, but Hat-on Perry = PERRY THE PLATYPUS?!?!? would go and now all I can see is that exact same situation with Doof being like:
"A snail?"
*Sergei proceeds to put on his hat very, very, very, very slowly*
*After a Sponge Bob Time-skip worthy amount of time in which Heinz is convinced some random snail has suddenly presented himself in his apartment*
"SERGEI THE SNAIL?!?!?"