The Opuntia fruit (cactus fig) is on the trail at the Mountains of the Moon. A woman is collecting them there.
The only "monster" on Nabooti Island is a monster tortoise, which you can lure with the Opuntia Fruit (cactus fig) found on the trail at the Mountains of the Moon.
You use it at the Kaya Forests to lure the sleeping tortoise.
At the Kaya Forests, there is a large tortoise sitting where you need to dig. Using the cactus fig (Opuntia fruit), you can lure him away.
It is in the Kaya Forest
The cactus fig (Opuntia fruit) is on the left side of the trail at the Mountains of the Moon. You need it to lure the tortoise at the Kaya Forests.
The cactus fig (Opuntia fruit) is on the trail at the Mountains of the Moon, just left of the woman you meet. Use it at the Kaya Forests to lure the sleeping tortoise.
You can get the tortoise to move by getting the Opuntia fruit (cactus fig) from the trail on the Mountains of the Moon. Once you lure the tortoise, you can dig at the spot. You are actually unearthing the Elephant Carving, which you will swap at Nabooti for the "fingo" (talisman) that the Kaya Spirits are seeking. They will give you the green jewel. (see related questions)
The cactus fig (Opuntia fruit) is on the left side of the lower trail at the Mountains of the Moon. You use it at the Kaya Forests to lure the tortoise out of your way. (see related question)
The cactus fig (Opuntia fruit) is from the trail at the Mountains of the Moon. Use it at the Kaya Forests to lure the sleeping tortoise away from where you need to dig. (see related question)
There is a lady that picks cactus figs (Opuntia fruit) on the trail at the Mountains of the Moon. You can get one from there. use it to lure the tortoise at the Kaya Forests so you can dig under it.
There is nothing IN the turtle, but there is something UNDER the turtle. To dig where the tortoise is sleeping, get the cactus fig (opuntia fruit) from the path at the Mountains of the Moon. Use it to lure the tortoise. To get a shovel, get the blue lily from the left side of the Blue Nile Falls, and swap it for a turban at Nabooti. Wear the turban at Giza to get a shovel.
The tortoise can be moved by luring it with a Cactus Fig (Opuntia Fruit) that is found on the upper trail at the Mountains of the Moon. Click "use" and the tortoise will eat the fig.