Requires

Yenna, Redtooth Regent must be on the battlefield. Three Blind Mice must be on the battlefield. Doubling Season must be on the battlefield. Yenna does not have summoning sickness. Mana needed:

Steps

1. Activate Yenna by paying and tapping it, creating two token copies of Three Blind Mice.
2. The Three Blind Mice tokens enter the battlefield with two lore counters on them due to Doubling Season, triggering their first and second chapter abilities.
3. Resolve the first Three Blind Mice triggers, creating four 1/1 Mouse creature tokens.
4. Resolve the next Three Blind Mice trigger, creating two token copies of a Three Blind Mice token.
5. Repeat from step 2.
6. Once you have infinite Three Blind Mice triggers, you may use them to copy any token(s) you control.

Results