Jersey Giant
Jersey Giants tend to look exactly like Australorps as chicks and adults, The only way you can tall them apart is their body shape and feet colors, THe bottom of an australorp would be a white-ish pink meanwhile the jersey Giant will have yellow skin under their feet
As adults Australorps will have a smaller, More of a longer body than a Jersey giant with a longer shaped head and tail, and would be noticeably smaller next to a JG. (Pic of Australorp)
Jersey Giants are very large, With thick plumage and a beautiful green/purple sheen. A shorter more round body and head.
(Pic of one of my Jersey Giant hens)

As adults Australorps will have a smaller, More of a longer body than a Jersey giant with a longer shaped head and tail, and would be noticeably smaller next to a JG. (Pic of Australorp)

Jersey Giants are very large, With thick plumage and a beautiful green/purple sheen. A shorter more round body and head.
(Pic of one of my Jersey Giant hens)