COTM#2 is an oldie: Phantasmal Forces
A 4/1 flying creature for 4 mana, but with an upkeep cost. This would still be a decent limited card now, but, back in the day, it was a popular casual card for our blue decks.If the opponent had no blockers or removal, they were dead in 5 turns. Creature power creep is a thing.
The usual curve was this into a 5-drop like Air Elemental or Vesuvan Doppleganger. Get to 6 mana? Mahamoti Djinn!
WUBRG - Notice how the very old version uses U instead of the rain drop mana symbol? The very early sets didn't seem to be able to print mana symbols in the text box, so you had to pay GGGG for Force of Nature's upkeep. I can imagine a new player seeing a 'U' and thinking, "I have to spend you during the upkeep"?
I loved the art on this, even though the forces don't look all that phantasmal.