Agatha's Soul Cauldron + Inquisitive Puppet + First Day of Class

Agatha's Soul Cauldron

Inquisitive Puppet

First Day of Class

How it works

1. Cast First Day of Class by paying 1.
2. Activate another creature you control that has a +1/+1 counter on it by exiling it, creating a 1/1 Human creature token.
3. When the Human enters the battlefield, First Day of Class triggers, putting a +1/+1 counter on it.
4. Repeat from step 2 using the Human token instead.