Berta, Wise Extrapolator (Secrets of Strixhaven)

Legendary Creature Ñ Frog Druid - Increment (Whenever you cast a spell, if the amount of mana you spent is greater than this creature's power or toughness, put a +1/+1 counter on this creature.)
Whenever one or more +1/+1 counters are put on Berta, add one mana of any color.
{X}, {T}: Create a 0/0 green and blue Fractal creature token and put X +1/+1 counters on it.