Metallic Mimic has at least one +1/+1 counter on it
"Insect" chosen with
Metallic Mimic
Steps
Activate
Metallic Mimic using
Grist's first loyalty ability by putting a loyalty counter on it, causing you to create a 1/1 Insect creature token and mill a card, and then put a loyalty counter on
Metallic Mimic and repeat the process if the card was an Insect
The Insect enters the battlefield with a +1/+1 counter on it due to