That said, Id prefer a commander with more than a single ETB effect, especially if that effect wont be too impactful until later in the game
Obelisk Spider Aside from spiders, Obelisk Spider has another natural home with Hapatra, Vizier of Poisons
Some of these cards can change which side is in use once they've already been played, via the Transform mechanic
Retrieve Prey One generic, one green sorcery Adventure: Exile target creature card from your graveyard
The One Ring Legendary Artifact Indestructible When The One Ring enters, if you cast it, you gain protection from everything until your next turn
When you play against a deck with a high density of removal spells, waiting to cast Pack Rat until turn 5 is just insane because it forces them to have two removal spells immediately