The Leather Hat is a rounded hat with the brim flipped up; a notch in the front exposes what appears to be a black band with a golden buckle wrapped around the base of the crown. As the name suggests, it is made of dark red Leather with thin gold trim around the brim; a small white skull and crossbones is printed on the right-front side of the brim as well.
As its menu description states, the Leather Hat is a very basic piece of headgear that modestly boosts most of the wearer's non-offensive stats. Its defenses are slightly below-average, but its HP boost is tied with the Viking Helmet for the highest of any male hat; it also grants incidental boosts to MP and Evade. This combination gives Matt or Lance a respectable increase to their overall bulk while giving them a slightly better chance to dodge attacks and a little more freedom to use their skills before needing to replenish themselves.
Unfortunately, the Leather Hat struggles to stand out against other hats with more specialized stats, superior resistances, and/or useful special effects. For one example, the Fuzzy Hat has almost identical stats - with a little less HP and a little more MP - but its resistances are generally much more useful (although it also suffers from a small Fire weakness).
The Leather Hat has a Stun resistance that maxes out at 50% at Level 5.