In 1977, after Daniel Faraday was killed by his mother Eloise Hawking, this unnamed Other was seen riding a horse and coming back to the camp along with his leader Charles Widmore. They found Jack and Kate peeking at their camp, so they attacked and captured them. Widmore hit Jack with his rifle, while this other pointed his rifle at Kate and asked her to stop moving.
Although the character had a few speaking lines, he wasn't credited in the episode. Instead, he was credited in a promotional photo solely featuring him.
The situation is similar to Radzinsky's gunmen and Nadine's, who were also credited in promotional photos only, but it is unknown why he wasn't credited in the episode consider he actually had lines, while the gunmen and Nadine have none.