What's the joke to this punch line?

And you won’t get many more with these prices!

…and the asylum superintendent gives the barman a trashcan lid and says, “Sorry, I don’t have anything smaller”.
“Because you’ve got Father O’Reilly’s slippers on!”
And God said, “You want that bridge four lanes or six?”
“How did I make the donkey cry? I showed him!”
“Naah, it’s not that. I just didn’t know the parrot had sold the place.”

This is really frustrating. I only know about one joke in four and no one is explaining. Just to get even -

“Where’s my cookie?”

You woke me up in the middle of the night for Moo Goo Gai Pan??

“Holy mackerel, where did all these fucking Indians come from?”

You know, most of these sound like bad ways to end a date rather than punchlines.

Somewhere Henny Youngman is feeling a great disturbance in the force, as if thousands of voices were laughing out loud and then suddenly silenced.

The old lady looked at her husband and said, “Every one of them.”

‘NO! It’s just ice cream!’

giggle This is fun. ^__~

[It seems odd, somehow, to see tomndebb in here. Always figured him for such a serious, button-down, no-nonsense kinda feller. :D]

The duck says “It started as just this little bump on my butt.”

ya know, Superman, you’re an asshole when you’re drunk

cuz he’s hung like this

no, you’re bloody ugly

a harmonica only sucks half the time

Did you just feel something?

“Oh, sure,” the wife says. “You don’t have to get up in the morning!”

“Great”, said the old lady, “I’ll keep my eye out for you”.

Well could we take a break anyway? I’m starving!

What do you mean us, paleface?

Sometimes the bull wins.

So the bear wiped himself with the rabbit!!!
“Why do you ask, ‘two dogs fucking?’”

Question 2 (95 points): Which tire?

[shameless attempt to increase posts count]

“Plus a constant!”

[/shameless attempt to increase posts count]

I’m an ex tractor fan myself

I’m afraid not (a frayed knot)

You wanna buy a fly?

But then when I have a baby, won’t it knock my teeth out?