MTG Bloomburrow black mana Mythic is one of the set’s best cards

MTG Bloomburrow’s Rottenmouth Viper is a card that many players will fear seeing arrive on an opponent’s board, thanks to its devastating burn damage and sacrifice-pushing mechanics. 

Rottenmouth Viper is a high-cost black mana Mythic Rare, coming in at a substantial cost of 5B. This high mana value is more than justified, however, as Rottenmouth Viper is a significant threat thanks to its bulky stats and powerful abilities. 

Even still, this card comes with a cost-reduction ability to help it hit the field earlier than when paying for its full mana value. The player casting Rottenmouth Viper may sacrifice any number of nonland permanents. If they do so, the casting cost of this card is reduced one generic mana per sacrificed permanent.

This cost reduction requires a more significant investment than something like Convoke, but sacrificing permanents can still be viable in decks heavy on token production methods like Bloomburrow’s Offspring. 

This card is a substantial presence in combat as a 6/6 but lacks any combat tricks to help it evade opponents’ blockers.  

Indeed, other players will be looking to kill this Creature as quickly as possible, as it comes packing an effect that triggers both on entry and whenever this Card attacks. 

On ETB or attack, Rottenmouth Viper gains a blight counter. As these tokens stack up, Rottenmouth Viper becomes all the deadlier, dealing 4 damage to each opponent per blight counter on this card. 

Other players do at least have a way out of taking this damage, which is only fair as the burn can quickly become lethal even in Commander, and even more so in Standard and other formats starting at 20 life. 

Sacrificing a nonland permanent or discarding a card is the only way to avoid this damage. But as this must be done on every ETB or attack, you can find yourself quickly being drained of resources and board presence when facing down this deadly viper.