Arcbound Mamba [Unknown Event] Transformers Tokens That creature cannot be regenerated

That creature cannot be regenerated this turn

{4}: Put a +1/+1 counter on Walking Ballista

Set: Friday Night Magic 2001 Type: Instant Rarity: Rare Cost: {1}{U} Look at the top four cards of your library

Set: Secret Lair Drop Series Type: Instant Rarity: Rare Cost: {1}{U} Return target creature to its owner's hand

Set: Double Masters 2022 Type: Land Rarity: Mythic As Cavern of Souls enters the battlefield

Arcbound Mamba [Unknown Event] Transformers Tokens That creature cannot be regeneratedSet: Unknown Event Type: Artifact Creature Snake Rarity: Common Cost: {3}{G} Deathtouch Poison Modular 2 (This creature enters the battlefield with two +1 +1 counters on it. When it dies, you may put its +1 +1 counters on target players or artifact creature. If they're put on a player this way, they become poison counters.)