Nettling Imp (Retro) [30th Anniversary Edition] 30th Anniversary Edition create a 0/0 colorless Construct

create a 0/0 colorless Construct artifact creature token with "This creature gets +1/+1 for each artifact you control

Traditional Foil Borderless Mythic Planeswalker in <1% of boosters

if you control the artifact with the highest mana value or tied for the highest mana value

if you chose a creature other than Gandalf

but I believe a more mundane power source might suffice

Nettling Imp (Retro) [30th Anniversary Edition] 30th Anniversary Edition create a 0/0 colorless ConstructSet: 30th Anniversary Edition Type: Creature Imp Rarity: Uncommon Cost: {2}{B} {T}: Choose target non Wall creature the active player has controlled continuously since the beginning of the turn. That creature attacks this turn if able. Destroy it at the beginning of the next end step if it didn't attack this turn. Activate only during an opponent's turn, before attackers are declared.