toilet salmon

Slang.

Unlike a Brown Toilet Trout which is gone when you flush the toilet a Toilet Salmon is a turd that when flushed returns like a salmon that swims upstream back to where it was spawned.

Example 1:
Holy cow, I flushed twice and I still can't get this toilet salmon to go down stream. What has that crazy vegan been feeding me?

Example 2:
A flushing sound heralds a momentarily soon to be unoccupied bathroom that upon departure of its user becomes occupied. The new occupant notices something left behind in the toilet where it is heard, "HEY Someone left a turd in here!"

The reply: "You can't blame me for a toilet salmon spawning season. I flushed."

Example 3:
"I flushed but if there are any toilet salmon in there you can't hold that against me."