In Dark Souls I, this is a combination of the Giant armor set and Mask of the Father, commonly used by an infamous min-maxing build (the build also includes Havel's Ring and the Ring of Favor and Protection, though this is not typically shown) the tag is named after, as shown in this video.
Aside from the armor and rings shown, the build tends to include a Chaos Zweihander (or Lightning Zweihander, you casul), Grass Crest Shield, Black Flame, and a stat build with the bare minimum to fast roll as well as wield the weapon two-handed (but don't tell anyone you leveled up DEX). The most common gesture done by players who use this build is "Well, what is it?", learned from Oswald of Carim.