"Call of the Mummy" is highly useful in a Zombie Deck. The fact that it will allow its controller to Special Summon high Level Zombiemonsters from their hand on their first turn makes it a formidable card.
This card can be very effective in a "King of the Skull Servants" Deck. If you already have multiple "Wights" in the "Graveyard", and no monsters on your side of the field, you can summon 2 Kings with possibly high attack.
Even if your opponent has monsters on their side of the field, if you equip "Opti-Camouflage Armor", you can attack directly with 2 high-powered monsters for a possible OTK.
This card combos well with "Dark Dust Spirit". Simply Summon any Zombie monster and then Tribute it for "Dark Dust Spirit", clearing the opponent's field.
Use this card to Special Summon "Il Blud", Normal Summon it, then have it Special Summon another high-Level Zombie from the hand or Graveyard.
Alternatively, Special Summon a "Zombie Master" and discard a lower Level monster to then Special Summon the discarded monster, or another in the Graveyard. The monster Special Summoned by "Zombie Master" won't be destroyed if "Il Blud" is destroyed.
Use this card to Special Summon a Zombie monster while having "Everliving Underworld Cannon" on the field to inflict 800 damage to the opponent.