His Wikipedia article says it best…
Eilert Pilarm is a Swedish Elvis impersonator whose fame (such as it is) stems from his striking lack of resemblance to Elvis Presley, both vocally and physically; his shaky command of the English language in which he sings; and his apparent absence of enough musical talent to recognize that he is usually out of tune and inaccurate with the timing of his singing.
Exhibit A: “Jailhouse Rock”
Exhibit B: “All Shook Up”