Examples:

• There's some connection in all this or I'll eat my hat.
• And if they suspend Schulz, I'll eat my hat.
• I'll eat my hat if, by some chance, my team loses to yours.
• There's something amiss And I'll eat my hat if this isn't love
• If he's 13, I'll eat my hat.
• I'll eat my hat if that's true.
• If you cry, I'll eat my hat.