The Harvest Feature randomly triggers in base gameplay, a tractor then ploughs over the reels unveiling a selection of the Wild Carrot symbols on the reels.
The free spins feature is triggered by landing the special Fat Rabbit symbol along with at least 1 Wild Carrot symbol on the reels (shown in the screenshots above) and grants an initial 5 free spins.
During the bonus round, you have a permanent wild symbol on the reels in the form of the Fat Rabbit, any additional Wild carrots that land in view during the free spins are eaten by the rabbit and will move the sticky wild symbol into that position for the next spin.
You will notice on the right-hand side of the screen a collection meter, filling this up with carrots will cause the rabbit to enlarge in size when filled, starting with a 2×2 sized symbol and then a 3×3 wild symbol and so on.
Filling up each level of this meter will also grant additional free spins.