Jump the shark? No, jump the snake:
When something that was hyped to be great turns out to be mediocre, especially when you really should have known better in the first place.
This differs from jump the shark because it refers to something that was never good to begin with, versus something that was good and went bad.
Ah, Urban Dictionary, you can be so harsh. You loved us in the past. What happened? What happened…

Weep not, my friend. This is the first and only mention of this phrase used in this context. I doubt it will ever catch on in the real world, as “Snakes on a Plane” = “whatchagonnado?” has.