The Tuurngait Infected are enemies from the game Penumbra: Black Plague (another game developed by Frictional Games) and only appeared in Amnesia: The Dark Descent beta gameplay video in the Wine Cellar.
Obviously, the Tuurngait Infected look identical to themselves from the Penumbra series; appearing as nude, palish-colored humanoids with red mouths and black eyes. They also have the same dialog lines like from Penumbra.
From the beta gameplay video, unlike from the actual Penumbra: Black Plague game, the Tuurngait Infected doesn't carry any equipment at all.
They were not actually intended to appear in the latter game, as they were for showcasing the concept of sanity.
As the final release of Amnesia: The Dark Descent, Tuurngait Infected are ultimately replaced by the game's own enemies - the Gatherers.
Tuurngait Infected can still be added to the game's custom stories (the "Madness Demo story" for example), however.
|The Dark Descent creatures|
|Gatherers||Servant Grunt • Servant Brute|
|Others||Kaernk • The Shadow|
|Unreleased||Spider • Tuurngait Infected|
|Suitors||Aloïs Racine • Basile Giroux • Malo de Vigny|
|A Machine for Pigs creatures|
|Manpigs||Wretch • Engineer • Tesla • Failed Experiments|
|Others||The Engineer • The Machine|