The Jolly Balloon Man and Intruder Alarm on the battlefield.
You control at least one creature that can tap to produce at least ({1} magic symbol) .
You control at least one additional nonlegendary creature.
Steps
Activate a creature by tapping it, adding ({1} magic symbol) .
Activate The Jolly Balloon Man by paying ({1} magic symbol) and tapping it, creating a token copy of another nonlegendary creature you control that is a 1/1 Balloon with flying and haste in addition to its other types.
When the creature token enters the battlefield, Intruder Alarm triggers, untapping all creatures.