A beaver was swimming in the river, and noticed a cow smoking on the shore.
"Hey, cow! Whatcha doin?"
"Nothing... Just chillin..."
"And what's that funky smelling cigarette?"
"Oh! That's pot. It helps you chill. Wanna try?"
The beaver took a puff and started coughing immediately.
"Dude! You need to hold it! Inhale... Waaaait... Exhale"
The beaver tried again, and choked again.
"You know what? You're a good swimmer, right? Let's do this: Inhale, swim across the river, and then exhale."
The beaver inhaled, started swimming, and in the middle of the river he felt so good, he emerged and had a fit of the giggles.
A hippo appeared and asked:
"What's so funny?"
"Nothing, man! The cow gave me some pot, and it's a blast!
You might get some too, if you ask!"
So the hippo swam across to the other bank, and as he was emerging, the cow spit out the joint and screamed:
"BEAVER! ... FOR CHRIST'S SAKE, ... EXHALE! EXHALE!"