If you don't control an Army, the Zombie Army token you create enters the battlefield as a 0/0 creature before receiving counters. Any abilities that trigger when a creature with a certain power enters the battlefield, such as that of Mentor of the Meek, will see the token enter as a 0/0 creature before it gets +1/+1 counters.
Grim Initiate
Amass abilities are now written as "amass [subtype] N." Previous cards with amass have received errata to say "amass Zombies N."
Amass Orcs works the same way, except you create a 0/0 black Orc Army creature token if you don't control an Army. If the Army creature you chose isn't already an Orc, it becomes an Orc in addition to its other types. By combining cards with amass Orcs and amass Zombies, you can end up with an Orc Zombie Army.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Jason Felix
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
