There are at least three total creatures on the battlefield.
Steps
Activate
Goblin Bombardment by sacrificing
Stag Beetle.
When
Stag Beetle dies, its persist ability triggers, returning it from your graveyard to the battlefield without a -1/-1 counter on it due to its replacement effect.
Resolve the
Goblin Bombardment ability.
Repeat.
Results
Infinite creature ETB.
Infinite creature LTB.
Infinite damage.
Infinite death triggers.
Infinite creature sacrifice triggers.
Metadata
Bracket tag
SpicyBracket 3-4+
Probably 3 or 4, but hard to classify
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5
1 · Exhibition5 · cEDH
Bracket tags are estimated from the cards and results of each combo, as a guideline rather than a strict classification.