Dropped by spear-wielding Lothric Knights.
The Lothric Knight Greatshield is the first available greatshield in the game, a massive tower shield with 100% physical damage absorption. It is relatively light for a greatshield, and has respectable stability, absorbing up to 71% of stamina damage when fully upgraded. However, its high Strength requirement prevents it from being easily used in the early game, though this can be circumvented by two-handing the shield with at least 24 Strength.
The Lothric Knight Greatshield has excellent resistance against Magic damage, but has moderate elemental defenses otherwise and in particular falls short in terms of Lightning absorption. This can make it useful against caster enemies, such as the Sage's Devouts located in the Road of Sacrifices and especially against the Crystal Sage. One may also get use of it when going through the Grand Archives, another location where Magic damage is abundant.
Reinforced with Titanite.