Here are the four cards I remember having a foil-only joke: Gleemax In foil, the art for Gleemax has the words "You Must Obey" written in tiny letters all over the art
Blink the summons right before they go away, and you have a nice engine going on, besides all the crazy stuff that you can do with Agent of Treachery or Atraxa, Praetors' Voice
Rhinos (29 players): The straightforward plan is to cast Shardless Agent or Violent Outburst on turn three to cascade into Crashing Footfalls, unleashing a horde of 4/4 Rhinos to quickly overpower the opponent
And even if you didn't, you could still play Historic that allows you to use cards now not Standard-legal you wouldn't need to stress about your deck being rotated out of use
Look, this isnt the best creature
This equipment costs two mana to cast, and it grants haste and shroud to any creature it's equipped to