When Azog enters,
destroyThe only ways a permanent can be destroyed are as a result of an effect that uses the word “destroy” or as a result of the state-based actions that check for lethal damage (see rule 704.5g) or damage from a source with deathtouch (see rule 704.5h). If a permanent is put into its owner’s graveyard for any other reason, it hasn’t been “destroyed.”
A regeneration effect replaces a destruction event. See rule 701.19, “Regenerate.” (CR 701.8) up to one other target creature. Its controller amasses Goblins X, where X is that creature's power. If you controlled that creature, draw a card. (To
amassTo amass [subtype] N means “If you don’t control an Army creature, create a 0/0 black [subtype] Army creature token. Choose an Army creature you control. Put N +1/+1 counters on that creature. If it isn’t a [subtype], it becomes a [subtype] in addition to its other types.”
A player “amassed” after the process described in rule 701.47a is complete, even if some or all of those actions were impossible.
The phrases “the Army you amassed” and “the amassed Army” refer to the creature you chose, whether or not it received counters.
Some older cards were printed with amass N without including a subtype. Those cards have received errata in the Oracle card reference so that they read “amass Zombies N.” (CR 701.47) Goblins X, that player puts X +1/+1
countersTo counter a spell or ability is to cancel it: remove it from the stack without resolving it. A counter on an object or player is instead a marker that changes characteristics or interacts with rules or abilities; for example, a +1/+1 counter modifies a creature’s power and toughness. (CR 701.6; 122.1) on an Army they control. It's also a Goblin. If they don't control an Army, they
createTo create one or more tokens with certain characteristics, put the specified number of tokens with the specified characteristics onto the battlefield.
If a replacement effect applies to a token being created, that effect applies before considering any continuous effects that will modify the characteristics of that token. If a replacement effect applies to a token entering the battlefield, that effect applies after considering any continuous effects that will modify the characteristics of that token.
Previously, an effect that created tokens instructed a player to “put [those tokens] onto the battlefield.” Cards that were printed with that text have received errata in the Oracle card reference so they now “create” those tokens. (CR 701.7) a 0/0 black Goblin Army creature token first.)