to spawn them naturally, if that's what you prefer. Ark | How to Spawn a Poison Wyvern w/ Console commands
Example (Level 150): cheat GMSummon "Wyvern_Character_BP_Poison_C" 150 Note: The final tamed level will be (roughly 225).
cheat Summon Wyvern_Character_BP_Poison_C 2. Spawn Fertilized Poison Wyvern Egg