I needed 5 copies of legendary beasts to complete the achievement. I copied Zixor, Apex Predator once. Then I drew Zixor Prime and copied it at least 7 times thanks to Brann, Dragon Breeder, and Zola copying the Tending Dragonkin. When the game was over my count for the achievement had only gone up by one.
Here’s the deck if it helps:
Custom Hunter
Class: Hunter
Format: Wild
2x (1) Fetch!
1x (1) Mystery Winner
2x (1) Rangari Scout
2x (1) Tracking
2x (2) Bargain Bin
2x (2) Birdwatching
2x (2) Dragon Breeder
2x (2) Explosive Trap
2x (2) Freezing Trap
2x (2) Messenger Buzzard
2x (2) Scavenger’s Ingenuity
1x (2) Titanforged Traps
1x (3) Brann Bronzebeard
1x (3) Exarch Naielle
2x (3) Stitched Tracker
1x (3) Zixor, Apex Predator
1x (3) Zola the Gorgon
2x (5) Tending Dragonkin
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