pig in a python n. especially in demographics, a spike or surge in a statistic measured over time. (source: Double-Tongued Dictionary)
Further reading
For at least three centuries, declaring I’ll eat my hat! has indicated that the speaker is so certain they’re right, that if they’re not, they’re willing to swallow their chapeau. Variations of this phrase include I’ll eat my boots, I’ll eat my cap...
The phrase throw in the towel meaning “give up,” stems from boxing competitions in the late 19th. If a boxer’s team wanted to stop the fight—usually because their fighter was taking too much punishment—they would literally throw a towel into the air...