Deathbloom Thallid and Tukatongue Thallid replace themselves with a Saproling when they die but wont ever make more than one
When played, Time Walk simply allows the user to take an extra turn (directly after the turn in which the card gets played)
Casting a card by using its retrace ability works just like casting any other spell, with two exceptions: You're casting it from your graveyard rather than your hand, and you must discard a land card in addition to any other costs
The First Sliver A deck with The First Sliver has a heavy restriction since it only lets slivers cascade, but slivers are the creature type to benefit from this mechanic
Did I miss your favorite undead bloodsucker
Of course, that gets stupid with cards like Necropotence or Griselbrand which allow for big life payments, and coupled with a card like Exsanguinate, you can recoup your life loss or even outright win