Every Zombies Dark Ops challenge — the hidden challenges that only reveal their name once completed — and the calling card each one awards, across Black Ops 3, 4, Cold War, 6, 7 and Infinite Warfare.
Black Ops Cold War introduced the Zombies ‘Dark Ops’ card system — hidden challenges earnable on any map (plus Dead Ops Arcade). Filter by category.

Reach Round 100.

Kill 1,000,000 zombies.

Reach Round 30 without going down.

Reach Round 20 without taking a hit.

Reach Round 20 with your starting loadout.

Hold 2 fully-upgraded weapons with ammo mods and 6 active perks.

Buy every Mystery Box weapon in one game.

Kill 50 enemies with a single Support.

Exfil a game using only melee attacks.

Complete any main Easter-egg quest.

Reach a cumulative Dead Ops Arcade score of 999,999,999.

Beat Mamaback (the DOA final round) without dying.

Complete the Dark Ops set.
Black Ops 4's Zombies ‘Dark Ops’ challenge cards (the full set is a known community gap). Filter by category.
Complete the main Easter eggs on all three launch maps (IX, Voyage of Despair, Blood of the Dead).

Reach Round 20 on classic Zombies without taking a hit.

Activate every perk modifier.
Complete all Zombies Dark Ops challenges.
Global ‘Dark Ops’ challenge cards — hidden until completed, earnable on any map. Filter by category.

Reach Round 100.

Kill 1,000,000 zombies (lifetime cumulative).

Reach Round 30 without going down.

Reach Round 20 without taking damage.

Reach Round 20 with your starting loadout only — no augments, perks, ammo mods or Field Upgrade.

Buy every Mystery Box weapon in a single game.

Consume 25 GobbleGums in a single match.

Get downed within 10s of consuming Perkaholic.

Hold 3 Pack-a-Punch-III Legendary weapons with ammo mods and 8 active perks.

Kill 100 enemies with a single Scorestreak.

Reach Round 25 solo using only melee / Combat Axes / Melee Macchiato.

Kill two Amalgams with a single shot.

Kill 10 ignited Elites using the Napalm Burst ‘Big Game’ augment.

In one Aether Shroud (Void Sheath), kill 3 standard + 2 Special + 1 Elite.

Complete 15 Dark Ops challenges.
Global ‘Dark Ops’ challenge cards plus mastery/prestige — earnable on any map. Filter by category.

Reach Round 100.

Reach Round 999.

Eliminate 1,000,000 zombies.

Reach Round 20 without taking damage.

Survive to Round 50 without going down.

Hold 3 Pack-a-Punch-III Legendary weapons with ammo mods and 8 perks.

Buy 30 Mystery Box weapons in a single match.

Kill 100 zombies with a single Scorestreak.

Drink Jugger-Nog 20 times in a single match.

Kill 1,000 zombies with each of the 8 dedicated Crew Operators.

Kill 100 zombies without reloading.

Reach Round 50 using only melee and Combat Axes.

Fully research all Augments.

Kill an Elite by launching it with a jump pad.

Reach Round 50 with the Dragon Wings + Lawyer's Pen relics active.

Complete 15 Zombies Dark Ops challenges.

Reach Prestige (harder at higher prestiges).
Black Ops 3 has few Zombies calling cards and mostly no per-map cards; its main-quest cards are on the maps themselves.

Complete all the Zombies story quests.

Enter Prestige after reaching Deresurrectionist (Zombies rank Lv 35).
Infinite Warfare's headline animated cards for its cross-map ‘super’ Easter eggs. Per-map Director's Cut cards are listed on each map; Fate & Fortune is a separate system.

Complete every Director's Cut Easter egg (also unlocks the Director's Cut Camo).

Complete ‘Sooooul Key’ as Willard Wyler.