You control another creature that has at least one +1/+1 counter on it.
Mana Needed
({G} magic symbol) ({U} magic symbol) available.
Steps
Activate
Zameck Guildmage's first ability by paying ({G} magic symbol) ({U} magic symbol) , causing each creature you control to enter the battlefield with a +1/+1 counter on it this turn.
Activate another creature you control that has a +1/+1 counter on it by exiling it, creating a 1/1 Human creature token that enters the battlefield with a +1/+1 counter on it due to Renata.