Energy Retrieval (59/73) [Sun & Moon: Shining Legends] Boar any time you could activate

any time you could activate a mana ability

Set: New Phyrexia Type: Instant Rarity: Common Cost: {3}{W} You gain life equal to the number of creatures on the battlefield plus the number of artifacts on the battlefield

Set: Commander 2016 Type: Artifact Rarity: Rare Cost: {3} Lands you control have "{T}: Add one mana of any color

Set: Fifth Dawn Type: Artifact Creature — Golem Rarity: Rare Cost: {11} Affinity for artifacts (This spell costs {1} less to cast for each artifact you control

But usually it's better to make a wall out of the wood and let trouble do the knocking

Energy Retrieval (59/73) [Sun & Moon: Shining Legends] Boar any time you could activateSet: Sun & Moon: Shining Legends Type: Item Rarity: Uncommon