a spooner
When you mess up your words by switching letters, usually because you're too busy being dumb to think straight.
I said 'flobber wick' instead of 'wobbler tick' and my friend laughed at me
I told my boss I wanted 'french slacks' instead of 'flicks socks' and he fired me
I said 'bithy wick' instead of 'witchy bick' and my friend asked if I was high