At Buffalo, it is the gold coin that triggers 8, 15 or 20 free spins when it appears 3, 4 or 5 times. 5 more free spins will be added if the gold coin reappears 3 or more times during a free spin....

Every time you win, Valley of the Gods triggers a re-spin. There is no limit to how many re-spins are possible. The more you win in a row, the more re-spins you get. ...

200 free spins as a bonus for Starburst....

3 or more pyramids trigger 12 free spins on Eye of Horus....

The book triggers 10 free spins on Book of Dead if 3 or more of them appear on the reels....

10 free spins are triggered by 3, 4 or 5 glowing orange crystal balls....

3, 4 or 5 moons are needed to trigger 12 free spins....

3, 4 or 5 pyramids trigger 10, 25 or 100 free spins accordingly....

Ramses Book requires 3, 4 or 5 books to trigger 10 free spins....