In the Back Garden challenge, you must collect thirty rabbits. When you get to number 29, the last rabbit is in the compost bin. Get Wallace near the compost bin. Then, press [L] to have Gromit call him. He will blast the lid off, but only briefly. Gromit must stand on the trap next to it, and be ready to catch the rabbit mid-air.

Press [A] then [B] to roll.