Biophagus
Creature — Human Tyranid Wizard
Genomic Enhancement — 
: Add one mana of any color. If this mana is spent to cast a creature spell, that creature enters with an additional +1/+1 counter on it.
"We guarantee you that within a week, you will feel like a new man." —Galaxos Klynesmith, biophagus
Teodora Dumitriu
Rulings
If Biophagus's ability produces more than one mana, perhaps due to an effect such as that of Mana Reflection, each creature cast with that mana will enter the battlefield with an additional +1/+1 counter. If all of that mana is spent on the same creature, it will enter the battlefield with that many additional +1/+1 counters.
(wotc • 2022-10-07)
Rulings
If Biophagus's ability produces more than one mana, perhaps due to an effect such as that of Mana Reflection, each creature cast with that mana will enter the battlefield with an additional +1/+1 counter. If all of that mana is spent on the same creature, it will enter the battlefield with that many additional +1/+1 counters.
(wotc • 2022-10-07)