pipsquack
The pipsquack was a rare and elusive bird being searched for by Tom and Jerry in the guise of nature photographers on the episode titled "Hold That Pose" from "The Tom & Jerry Show" circa 1975. The legendary bird was theretofore never seen, but known only by it's intensely annoying, loud, and oft-repeated call of PIPSQUACK!, until the end of the episode, when, upon finally discovering the bird, a cacophony of pipsquacks emerge from the jungle.

The call of the pipsquack is so irritating that is is burned into the memory of most Gen-Xers, despite them having usually forgotten the show that it was featured on.

PIPSQUACK!
PIPSQUACK!...

PIPSQUACK! ad infinitum.