Slay

The slay on-hit item property on a weapon causes a creature hit by the weapon to be killed if it matches the type of creature specified in the property name. There are three ways in which creatures can be specified &mdash; by alignment, by alignment group (e.g. good), and by race.

There is also a "slay rakshasa" property implemented as an on-hit: cast spell property. This property's official name is "blessed bolt properties", not "slay" though.