Blood Moon
One mana cantrips drawing you two cards each
This one is a bit off the deep end, as nobody is doing anything too broken with Street Wraith at present, but it falls under the same paradigm of "free stuff is bad." Right now the worst things that Street Wraith does are allow for far too early Death's Shadows and help power out Hallowed Ones on turn one, and these sorts of ahead of the curve draws add a lot of volatility to the format
But if you want to know which commons are the most expensive regardless of reprints, or the most expensive cheapest-printed version commons around, Ive got you covered
Commander Greven il-Vec was awesome when I was a kid, but he's not nearly as good nowadays and I'd much rather have the newer Greven, Predator Captain instead, in all his Hatred-bearing glory
Toski, Bearer of Secrets doesn't fit the Ooze theme, but it's an indestructible creature that gives the rest of your creatures a Curiosity effect, turning every successful attack into more cards in your hand