Darkness Mimicry – The being is composed of shadow.
Nightshade (DC) can turn into a shadow (DC Who’s Who in the DC Universe V1 #5).
Obsidian (DC) is a superhero that can turn into a shadow (DC Who’s Who #17).
Shadow-Thief (DC) is a supervillain that can turn into an apparent shadow.
Major and minor characters were turned into shadow beings all the time in the DC Silver Age (Detective Comics V1 #284, House of Secrets V1 #57, Mystery in Space V1 #78, World’s Finest V1 #126).
Shadowpax (Lone Star) cannot be teleported because he is shadow which is the absence of anything according to Doctor Odd in Pantheon #3 (Lone Star Press).
Warlord Kaa (Marvel) is a monster in the Marvel Monsters-From the Files of Ulysses Bloodstone.
The Shadow Strangler is raw darkness that as the name suggests can strangle humanoids (D&D 4th Edition – Monster Manual 3).
The Shades are cowardly creatures (World of Warcraft Monster Guide).
The Void Walker can absorb shadow for self healing (World of Warcraft Monster Guide).
Nightwalker – D&D 3.5 – Monster Manual I
Nightwalker – D&D 4th Edition – Monster Manual 1
Shadeling – TSR 2145 Monstrous Compendium Annual Volume 1
Shadow Alien – Tales of Suspense V1 #7
Shadow Lord – Creature Collection II. Dark Menagerie
Shadowman – Creature Collection I
Slarecian Shadowspawn – Creature Collection II. Dark Menagerie
I am not sure what a shadow locus is but I don’t want to meet one!
Next 123) Death Sense