Those include ones with powerful EtB effects, powerful ongoing effects, ones that dominate the board and ones that are really hard to deal with
Since it's a 1-mana creature, it can be searched for with "Ranger-Captain of Eos"
More draw helps you hit the removal, the interaction, and the recursion you need, without sacrificing as many deck building slots as you would for ramp
From the creature boost to the mana acceleration to the ability to use your Acidic Slime to kill nearly anything, the card will pay dividends
Dig Up is always considered a green card, but its a green-black card for Commander's color identity purposes
Combo this card with spells that allow you to steal creatures from your opponent's graveyard for max value