This is the Self family crest as it appeared originally. Notice the spelling of the family name is "Saewulf." The name "Self" is actually a corruption of the original Nordic / German which meant "Sea Wolf" in English.
This is the Self family crest as it appears today. The shield itself remains unchanged, insomuch as it contains the white or gray flowerd cross set on a green shield. You will notice the name has been changed to spell the modern family name of "Self." and the country of origin as England, which is not geographically correct.