Gollum the Abandoned

Azog can destroy Gollum to draw a card and amass Goblins 2, after which Gollum can be returned to hand and replayed for another drain trigger.

Allure of Power sacrifices Gollum to draw two cards, and Gollum's recursion lets you recover and replay him rather than permanently losing the creature used for the additional cost.

Each chapter can blink Gollum, repeatedly retriggering his enter-the-battlefield graveyard exile and 2-life drain while also resetting him after combat.

Sacrificing Fearsome Goblin Pair to return Gollum from the graveyard also triggers amass Goblins 4, converting Gollum's recursion cost into a large Army while setting up another Gollum cast and drain.

Each time Gollum returns itself from your graveyard to your hand, Along the Crooked Way amasses 1. Gollum's sacrifice cost also helps stock the graveyard with other creatures for the enchantment's enters ability.

Sacrificing Getaway Barrel to Gollum's graveyard ability both returns Gollum to hand and triggers the Barrel to put a random creature onto the battlefield, converting the recursion cost into a major tempo and card-advantage swing.

Gone Fishing can blink Gollum alongside another permanent, retriggering his 2-life drain and graveyard interaction without requiring him to die and be recast from hand.

When Gollum is sacrificed to another effect, Part in Friendship replaces him with another creature while Gollum can subsequently return to hand, turning the sacrifice into additional board and card advantage.

Activating Gollum's graveyard ability triggers Elrond to draw a card, adding immediate card advantage to Gollum's existing recursion loop once each turn.

Sacrificing Gollum to the Trolls draws two cards, and he returns to be eaten again — repeatable card advantage.

Chapter II can return Gollum after chapter I discards it, immediately retriggering its graveyard exile and 2-life drain.

Dancing from Dark to Dawn's Bear tokens provide expendable creatures for Gollum's recursion, and each recast Gollum then triggers the enchantment to place two +1/+1 counters on a creature.

Gollum's enter-the-battlefield trigger makes each opponent lose 2 life, causing The Master of Lake-town to mill that opponent for two cards; recurring and recasting Gollum repeats both effects.

Gollum can be sacrificed as Stir Up Trouble's additional cost to destroy an opposing creature, then later returned to hand and recast for another 2-life drain.

Snowslope Hunter can sacrifice Gollum after combat to generate an extra playable card; Gollum can then be recovered by sacrificing another expendable artifact or creature and replayed for its drain trigger.

Rhovanion Rampager can sacrifice Gollum while attacking to gain two +1/+1 counters, while Gollum's recursion lets you recover and replay the sacrificed creature for another drain.

Mirkwood Nurturer can return Gollum from the battlefield to your hand, gaining a +1/+1 counter and allowing Gollum to be recast for another graveyard-exile and 2-life-loss trigger.

Sacrificing a creature to return Gollum from the graveyard causes a creature to die, reducing Dreaded Bat-Cloud to a one-mana 4/2 flying deathtouch threat while also setting up another Gollum cast.

Front Porch Sentries is productive fodder for Gollum's recursion ability: sacrificing it returns Gollum to hand while also giving an opposing creature -1/-1 for the turn.

Gollum can be sacrificed to The Sackville-Bagginses, but it does not return automatically. Afterward, during a main phase with an empty stack, you may pay {2} and sacrifice another artifact or creature to activate Gollum's graveyard ability and return it to your hand.

Bolg can sacrifice Gollum for 2 damage, and Gollum can later be returned from the graveyard to reuse its enters ability. However, recovering and recasting it costs four mana and requires sacrificing another artifact or creature, so it is not freely reusable ammunition.

The creatures sacrificed to recur Gollum trigger Great Fierce Bee's scry ability, adding card selection to each iteration of Gollum's recursion engine.

If Gollum is placed in the graveyard pile, his sacrifice ability can return him to hand, recovering a card that would otherwise be lost.

The Food artifacts created by Supper for Spiders provide expendable sacrifice fodder for Gollum's graveyard-recursion ability without costing you creatures.