Toymaker and Basalt Monolith do not have summoning sickness.
You have at least one card in hand.
Steps
Activate Basalt Monolith's first ability by tapping it, adding ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) .
Activate Toymaker by paying ({1} magic symbol) , tapping it, and discarding a card, causing Basalt Monolith to become an artifact creature until end of turn.
Activate Basalt Monolith's second ability by paying ({1} magic symbol) , untapping it.
Activate Basalt Monolith's first ability by tapping it, adding ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) .