Where someone shits into a condom, freezes it, then uses it as a dildo.
I gave your mom the good-ol' trans-alaskan pipeline last night!
When someone goes to the bathroom, finds a log that is hard, and places that log into a condom. They then place the filled condom in the freezer and once it is hard, use it as a dildo.
That girl was do broke she could not buy a dildo so she ended up making a Trans Alaskan Pipeline.
Two people/animals put each others assholes together as if their assholes are kissing, then one proceeds to shit from their asshole into the other asshole without breaking the pipeline and letting shit fall out onto the floor.
Leroy and Lafonda performed the trans-alaskan pipeline because Lafona was anorexic and never had to shit, so she wanted to borrow some of Leroy's.