Vizier of Remedies + Bloodflow Connoisseur + Grazing Kelpie
Vizier of Remedies
Bloodflow Connoisseur
Grazing Kelpie
Infinite +1/+1 counters on a creatureInfinite creature ETBInfinite creature LTBInfinite death triggersInfinite creature sacrifice triggers
How it works
Activate Bloodflow Connoisseur by sacrificing Grazing Kelpie.
When Grazing Kelpie dies, its persist ability triggers, returning it from your graveyard to the battlefield without a -1/-1 counter on it due to Vizier of Remedies.