Within weeks, more slivers nested in Otaria than ever existed on Rath.

Brood Sliver

Whenever a Sliver deals combat damage to a player, its controller may put a 1/1 colorless Sliver creature token into play.

Whenever a Sliver deals combat damage to a player, its controller may create a 1/1 colorless Sliver creature token.

Commander Masters

Whenever a Sliver deals combat damage to a player, its controller may put a 1/1 colorless Sliver creature token onto the battlefield.