A creature you control has at least one +1/+1 counter on it.
({1} magic symbol) available.
Steps
Activate Ghave's first ability by paying ({1} magic symbol) and removing a +1/+1 counter from a creature you control, creating two 1/1 Saproling creature tokens.
Activate Ashnod's Altar by sacrificing a Saproling token, adding ({C} magic symbol) ({C} magic symbol) .
Activate Ghave's second ability by paying ({1} magic symbol) and sacrificing a Saproling, putting a +1/+1 counter on Ghave.