Humorous:
* "Now, I ain't one to brag, but that catfish I caught was bigger'n a houseboat, and I'm tellin' you, it had teeth like a banjo pickin' bear!"
* "Let me tell you about the time I met a squirrel who could talk, play the fiddle, and wore a monocle."
* "My grandma always said, 'Never trust a man with a beard the color of a ripe watermelon,' and she was right, because that's the day I met a man who could grow trees out of his nose."
Mysterious:
* "The fog rolled in thick that night, and when it lifted, a giant, glowing beetle with eyes like burning coals stood on the mountain peak."
* "The old folks whispered tales of a hidden valley where the river flowed backward and the trees spoke in riddles."
* "The moon was as red as blood that night, and the old woman's prediction came true - the mountains themselves started to sing."
Action-packed:
* "The moment the coyote howled at the full moon, the ground began to shake, and a whole herd of wild mustangs stampeded straight through our town square!"
* "I was ridin' through the desert, hotter than a blacksmith's forge, when a tornado full of armadillos whipped up outta nowhere!"
* "With a lightning-fast draw, I whipped out my lasso and caught the runaway meteor before it could crash into the town."
Remember, the key to a good tall tale opening is to grab the reader's attention and make them want to hear more!