It's a bit curious. Supposedly Laugh-In's Arte Johnson (20 Jan 1929-03 Jul 2019) was born in Brent Harbor, Mich and has a twin brother named Coslough "Cos" Johnson who outlived him.
Yet, do a search and a curious fact emerges -- the date and birth certificate are in Chicago, Illinois {Certificate Number: 2350 Illinois, Cook County, Birth Certificates} and there is no mention of a twin by any name ... there is a brother, Howard Leonard Johnson, who was born on 08 Nov 1931 {Certificate Number: 45677}.
Does the twin exist? Or did Howard pass himself off as a twin brother? Or maybe, Arte used the twin to "moonlight" as a writer. In any event, where is COS? are there photos that are post-Arte's death -- maybe at the funeral?
Since Arte just died, we will see in a few days ... Arte's family are Russian Jews, so the funeral should be down within three days or so.
UPDATE 5 JULY 2019 --
This appeared as a correction or addition (after 4 July Notes from Shreknangst (49080548)) on FIND-A-GRAVE: "Edith Johnson, nee Goldberg, beloved wife of the late Abraham, loving mother of Arthur “Arte” (Gisela) of California, and Howard “Cos” (Mary Jane) of California; fond aunt and great-aunt of many. Service and interment Wednesday, 11 a.m., at Westlawn Cemetery, 7801 W. Montrose, Norridge. Contributions to the charity of your choice. Info, The Weinstein Brothers Chapel, 312-761-2400. —Chicago Tribune, 8 Oct 1996, SW_A8
It would seem the Arte Johnson award-winning "TWIN" mentioned in WIKIPEDIA is really his baby brother.
More inconsistencies are emerging.