This one isn't based on folklore, but yes, the appearance is loosely derived from little green men. Because why not. Not a spacefaring race, but an extraplanar humanoid that merely sees things very differently. Enjoy.
Doppler
by Cab Davidson
| Stat | Doppler |
| AC: | 4 |
| HD: | ½** |
| Move: | 900’(300’) |
| Attacks: | 1 weapon |
| Damage: | By Weapon -1 |
| Number Appearing: | 3d4 (8d8) |
| Save As: | F1 |
| Morale: | 8 |
| Treasure Type: | Q (D) |
| Intelligence: | 11 |
| Alignment: | Neutral |
| XP Value: | 7 |
Dopplers are strange humanoid creatures known from various outer planes dominated by the sphere of time. They are slim, short (rarely taller than 5’), hairless green skinned humanoids with lithe, muscled bodies. Whatever differences there are between the sexes of the dopplers is unknown. Young have been observed, practices involved in their creation are kept among the dopplers.
They are best known for their immense speed. They are quite simply faster than any other humanoids found, and frequently enjoy the use of items conferring haste on top of that. The consequence of their immense speed is that they are, if not surprised by a foe, able to attack with +3 to hit, they gain +4 to initiative, and all attacks against them are made at -4 to hit, their speed being so great that they often appear to be in front or behind where they are. Indeed they movements may be so fast that they appear to change colour in motion – at top speed running away they appear red, whereas when running at a creature they may be violet.
While their great speed might be assumed to make them fearsome enemies, it also means they have developed little interest in combat. There is no fight they cannot run away from, almost no danger they cannot avoid, hence in their culture standing and fighting an enemy is not seen as noble, it is understood to be stupid, dangerous and wasteful. While an excellent survival strategy, this has frustrated many immortals of time who have been unable to inspire dopplers to become adventurers, rulers, or along any other pathway that mat eventually lead to immortality.