Cryptic Trilobite has at least three +1/+1 counters.
Steps
Activate Cryptic Trilobite's first ability by removing a +1/+1 counter from it, adding ({C} magic symbol) ({C} magic symbol) that can only be spent to activate abilities.
Activate Ghave's first ability by paying ({1} magic symbol) and removing a +1/+1 counter from Cryptic Trilobite, creating a 1/1 Saproling creature token.
Activate Ghave's second ability by paying ({1} magic symbol) and sacrificing the Saproling token, putting three +1/+1 counters on Cryptic Trilobite.
Repeat.
Results
Infinite +1/+1 counters on Cryptic Trilobite.
Infinite colorless mana that can only be spent to activate abilities.