Muppet
Muppet. Somebody who acts in a way that the speaker considers ignorant or idiotic - 'you're a muppet!' Very friendly kind of tone attached to this word, jocular, affectionate, even. It's much less forceful than, 'idiot' or 'prat' or 'fool'. The tone of voice has got to be jocular. I just can't think of it as a vicious term - I couldn't say 'you horrible muppet!' - that doesn't work for me, though I can imagine some people might use it.
The implications, of course, are - because it's an inanimate thing - that the mind has gone elsewhere, you're being controlled by another, you're being clumsy - it's because the word comes from 'puppet' really, and that's the way puppets act.
The Muppets were, of course, a Jim Henson creation back in the 1970s - you know, Kermit the Frog in 'Sesame Street' and, of course, 'The Muppet Show' from that time onwards. Jim Henson once said that he just made the word up because it sounded good, but when he was pressed, he said it was actually a combination of 'marionette' and 'puppet', and it goes right back to the 1950s.
Well, it's developed all sorts of other uses since - have you ever heard of 'muppetry', for instance? That's a group of people behaving like Muppets! You know, sort of, automata, they're not thinking straight!
Oh, by the way, you have to distinguish it from 'moppet' - that's different - that's a charming, doll-like, little child, often with a mop of hair. Moppets aren't Muppets!
http://www.bbc.co.uk/worldservice/learningenglish/radio/specials/1453_uptodate3/page14.shtmlhttp://www.bbc.co.uk/worldservice/learningenglish/language/uptodate/I've come to use quite a few British colloquialisms in daily conversation, and they've worked swimmingly...