A rare heavy aggro black deck is currently quite popular, using the aforementioned Lurrus, as well as Ikoria mythic rare Fiend Artisan
Whenever you sacrifice a Food, target creature you control gets +X/+X until end of turn, where X is the number of quest counters on Sierra
River Merfolk River Merfolk is a bit of a weird one
1 Wildcard of any rarity A common (4.2%), uncommon (74.1%), rare (16.7%), or mythic rare (2.6%) from the Magic: The Gathering | Avatar: The Last Airbender main set An uncommon scene card (less than 1%) A rare or mythic rare scene card (less than 1%) A rare or mythic rare field notes card (less than 1%) A rare or mythic rare battle pose card (less than 1%) A rare or mythic rare elemental frame card (less than 1%) A mythic rare borderless double-faced Saga card (less than 1%) 1 Rare or mythic rare A rare (80%) or mythic rare (12.6%) from the Magic: The Gathering | Avatar: The Last Airbender main set A rare (1.6%) or mythic rare (less than 1%) scene card A rare (1.4%) or mythic rare (less than 1%) field notes card A rare or mythic rare battle pose card (less than 1%) A rare (2.4%) or mythic rare (less than 1%) elemental frame card A mythic rare borderless double-faced Saga card (less than 1%) 1 Traditional foil card of any rarity A common (53.9%), uncommon (36.7%), rare (6.7%), or mythic rare (1.2%) from the Magic: The Gathering | Avatar: The Last Airbender main set An uncommon scene card (less than 1%) A rare or mythic rare scene card (less than 1%) A rare or mythic rare field notes card (less than 1%) A rare or mythic rare battle pose card (less than 1%) A rare or mythic rare elemental frame card (less than 1%) A mythic rare borderless double-faced Saga card (less than 1%) 1 Land card A non-foil common dual land (40%) A non-foil default frame basic land (20%) A non-foil Avatar's journey basic land (10%) A non-foil Appa basic land (10%) A traditional foil common dual land (10%) A traditional foil default frame basic land (5%) A traditional foil Avatar's journey basic land (2.5%) A traditional foil Appa basic land (2.5%) 1 Non-foil DFC helper card or double-sided token Note: Percentages may not sum to 100 due to rounding
Its also great in decks that care about making tokens or artifacts for free, like Chatterfang, Squirrel General
For triggered abilities, the key words to look for are At, When, or Whenever
