A man goes into a pub accompanied by another - very small - man, no more than a foot and a half tall. They find a table and the taller man takes a keyboard out of his bag, which the tiny man then begins to play very skillfully, and he also takes a frog out of his pocket.
He gets chatting to the landlord, who is very impressed with the music, and he asks him what's with the frog. The man tells him that the frog is a genie who will grant wishes. He's highly proficient in the magic arts but there's just one small drawback....
The landlord is wide-eyed and, before the man can explain any further, the landlord says "Hey, genie-frog - can I have a million pounds, please?!" Instantly, he hears a deafening barking sound and goes out to the street, where there's an endless sea of basset hounds for as far as his eyes can see.
Meanwhile, another punter has overheard and has a go. He says "Hey, genie-frog - can you replace my little cottage with an enormous house, please?!" He rushes to the window and looks over the road, where he lives and, instead of his little home, there's now a 100ft-high mouse there.
They both look back to the man who brought the frog in and say "Well, he's absolutely amazing, but he does seem to be little deaf, doesn't he?!"
The man replies, "Yes, that's what I was trying to tell you before you rushed in with your wishes. Do you think I really asked him for an 18-inch pianist?!"