12km eggs - also known as 'Strange' or red Eggs - were first made available in October 2020 as part of a Team Go Rocket event. The Strange Egg pool was last updated on Wednesday 15th January.

Throh, Sawk, Heatmor and Durant can be obtained through two different means during Go Tour: Unova Global ... though I'd recommend saving those for 12km eggs. The second way you can find Throh ...