Requires

Urza, Prince of Kroog must be on the battlefield. Mycosynth Lattice must be on the battlefield. Biomancer's Familiar must be on the battlefield. Urza, Lord High Artificer must be on the battlefield. Mana needed:

Steps

1. Activate Urza, Prince of Kroog by paying , creating a token copy of Biomancer's Familiar that is a 1/1 Soldier in addition to its other types.
2. Activate Urza, Lord High Artificer's first ability by tapping the Biomancer's Familiar token, adding .
3. Activate Urza, Prince of Kroog by paying , creating a token copy of Biomancer's Familiar that is a 1/1 Soldier in addition to its other types.
4. Activate Urza, Lord High Artificer's first ability by tapping the Biomancer's Familiar token, adding .
5. Activate Urza, Prince of Kroog by paying , creating a token copy of Biomancer's Familiar that is a 1/1 Soldier in addition to its other types.
6. Activate Urza, Lord High Artificer's first ability by tapping the Biomancer's Familiar token, adding .
7. Repeat from step 5.

Results