Thunderbird is a 5-reel, line online slot game with download, bonus spins, instant play, autoplay, video slots, multiplier, wild symbol, expanding wild. . Thunderbird is a 5-reel, line online slot game with download, bonus spins, instant play, autoplay, video slots, multiplier, wild symbol, expanding wild. Thunderbird is a 5-reel, line online slot game with download, bonus spins, instant play, autoplay, video slots, multiplier, wild symbol, expanding wild.