World Enchantment, 2BB (4) Cumulative upkeep {1}{B} At the beginning of each upkeep, if Tombstone Stairwell is in play, each player puts into play a 2/2 black Zombie creature token with haste named Tombspawn for each creature card in his or her graveyard. At end of turn or when Tombstone Stairwell leaves play, destroy all tokens put into play with it. They can't be regenerated.1
Illus. Dom!
You control the triggered ability, but each player controls the token creature they put into play due to the ability's effect. [D'Angelo 1999/07/10]
All the tokens are put into play simultaneously. [D'Angelo 1998/11/16]
All tokens are owned by the controller of this card, and when the tokens go to the graveyard, they go to that player's graveyard. [D'Angelo 1997/11/14]
Both the cumulative upkeep and the triggered ability trigger at the beginning of upkeep, so you can choose what order they resolve. [D'Angelo 1999/07/10]
The haste ability is an initial ability of the tokens. This ability can be removed by Humility. [D'Angelo 1999/07/10]
Does not put the Zombies into play if this card is not still in play when its ability resolves. [D'Angelo 2001/06/01] (This puts the ruling back to the way it was before 2001/03/07 errata changed it.)
If something changes the names of the tokens, then the "at end of turn" ability will still destroy them. [D'Angelo 2003/08/01]