Pinkie Pie's contact calls her "Agent 3.14159265358979323846264" before being cut off.
Agent 3.14 needs to get past the janitor of Ponyville's school without being recognized. She simply walks by and says "Good morning."
Somehow, Pinkie Pie managed to pass unobserved with an Einstein disguise comprised of a white wig, a fake mustache, and an old lab coat along with her tongue sticking out, just like the famous photograph◊.
Which leads to this conversation:
Pipsqueak: Did you just see what I saw?
Rumble: You mean a pink pony with a paper mache scientist head and her tongue out?
Rumble: (Gulps) Let's both pretend we didn't see that.