The Duke, Rebel Sentry is a uncommon Legendary Creature — Human Rebel Ally card from Avatar: The Last Airbender Eternal (TLE), collector number 76. Current market price: $0.23 (foil $2.45), TCGplayer market prices via Scryfall.
The Duke enters with a +1/+1 counter on him. {T}, Remove a counter from The Duke: Put a +1/+1 counter on another target creature you control. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)