When this card is Normal Summoned: You can send 1 Zombie monster from your Deck to the GY. If this face-up card in its owner's control leaves the field because of an opponent's card effect: You can Special Summon 1 Level 4 or lower Zombie monster from your Deck, except "Samurai Skull".
Put Bacon Saver into the graveyard so that you can use his effect later to protect your monster from an opponent's attack.
Samurai Skull is an excellent opening play for Vampire decks because it allows them to get Vampire Familiar or Vampire Retainer into the graveyard where they can special summon themselves and trigger their search effect. If Samurai Skull is destroyed by your opponent's card effect you can also Special summon these monsters from your deck and trigger their search effect.
Tbh, hitting vampire grace or kingdom sounds like a more reasonable hit. Limiting skull hurts not only vampires but other zombie decks. If Konami wanted vampires to go, they could have hit the two I mentioned above. So when they release more zombies there won’t be any limitations
They won't touch this card, because the deck is not being overused.
Thought I'd mention an interesting scenario (no official ruling on yugioh wikia though, just by observation). If Samurai Skull has been returned to the deck by Drowning Mirror Force, it is not considered to have "left the field by the opponent's card effect", and its effect doesn't activate.