Animation Module | Mana Echoes | Cathars' Crusade

Cards

Put a +1/+1 counter on any creature you control.
Animation Module triggers, causing you to pay ({1} magic symbol) to create a 1/1 Servo artifact creature token.
When the Servo enters the battlefield,
Mana Echoes and
Cathars' Crusade trigger.
Resolve the
Mana Echoes trigger, adding ({C} magic symbol) for each Servo you control.
Resolve the
Cathars' Crusade trigger, putting a +1/+1 counter on each creature you control.
Animation Module triggers for each counter placed this way.
Resolve all but one
Animation Module trigger, choosing not to pay.
Resolve the final
Animation Module trigger, causing you to pay ({1} magic symbol) to create a 1/1 Servo artifact creature token.
Repeat from step 3.