You control at least two other nontoken creatures.
Steps
Activate at least three nontoken creatures you control except Othelm and Llanowar Druid by tapping them, adding at least ({G} magic symbol) ({G} magic symbol) ({G} magic symbol) .
Activate Llanowar Druid by tapping and sacrificing it.
Holding priority, activate Othelm by paying ({2} magic symbol) and tapping it, returning Llanowar Druid from your graveyard to the battlefield tapped.
Resolve the Llanowar Druid ability, untapping all Forests.