When it finishes the harvest, you'll have nowhere to hide.

Farmstead Gleaner

This creature doesn't untap during your untap step.
{2}, {Q}: Put a +1/+1 counter on this creature. ({Q} is the untap symbol.)

The List

Modern Horizons

Farmstead Gleaner doesn't untap during your untap step.
{2}, {Q}: Put a +1/+1 counter on Farmstead Gleaner. ({Q} is the untap symbol.)

The untap symbol, {Q}, functions the same as the tap symbol, only mirrored. You can’t pay the {Q} cost if Farmstead Gleaner is already untapped, and you must have controlled the creature continuously since your most recent turn began in order to pay {Q}.

Untapping an attacking creature doesn’t remove it from combat.