This has only happened once to me, but it was enough to weird me right out. About 10 minutes into a game as Vayne, my Berserker's Greaves suddenly turned into an elixir of agility! I was very confused. Putting my mouse over it gave me two descriptions, the BG description, but it also gave the name, description and picture of the EoA. I went into the shop to look at the area for the Greaves themselves, and it still showed the Elixir picture... so apparently boots + dagger = elixir? Lol. Picture of it will be attached, sorry for the crummy quality, it's off my phone. The Greaves still worked normally, it was just a very, very strange bug.
-Nurucio