"The penalty for idleness is death. The penalty for disputing the penalty is death."

Sengir Autocrat

When this creature enters, create three 0/1 black Serf creature tokens.
When this creature leaves the battlefield, exile all Serf tokens.

The List

Eternal Masters

When Sengir Autocrat enters the battlefield, put three 0/1 black Serf creature tokens onto the battlefield.
When Sengir Autocrat leaves the battlefield, exile all Serf tokens.

"A thankless job, and a death sentence besides."
—Eron the Relentless

Time Spiral Timeshifted

When Sengir Autocrat comes into play, put three 0/1 black Serf creature tokens into play.
When Sengir Autocrat leaves play, remove all Serf tokens from the game.

Classic Sixth Edition

When Sengir Autocrat comes into play, put three 0/1 black Serf creature tokens into play.
When Sengir Autocrat leaves play, remove all Serf tokens from play.

"Evil is relative. Do sheep think any better of the shepherd?"
—Baron Sengir

Fifth Edition

When Sengir Autocrat comes into play, put three Serf tokens into play. Treat these tokens as 0/1 black creatures.
If Sengir Autocrat leaves play, bury all Serf tokens.

If Sengir Autocrat leaves the battlefield while its first ability is on the stack, its second ability triggers and exiles any Serf tokens that happen to be on the battlefield, and then its first ability resolves and gives you three Serf tokens.

Sengir Autocrat’s last ability exiles all Serf tokens, not just the Serf tokens its first ability created.