When you die any familiar you had summoned will disappear and will drop any items they were holding on the ground where they were standing when you died. However unlike items carried by the player, items dropped this way will only be visible to the familiar's owner for a short period of time, similar to when items are dropped normally. Thus many players use familiars to hold items so that upon death the items may be reclaimed, preventing one from having to make new ones - this is particularly common with runes.