2020 Dollar mule
On 11th November 2020, photos of a PCGS slab containing a 2020 Mob of Roos $1 muled with a 10c obverse die were posted on a Facebook error coins group. The slab in question was https://www.pcgs.com/cert/40222602 and showed a 2020 Mob of Roos $1 with a heavily clashed 10c obverse (part of the lyrebird are visible around the Queen's head). It was reported as having been discovered in a mint bag.
Currently it is the only known example and there have not been any public sales.