The Satyrs were originally men with horses' haunches and tails, two-legged as opposed to the four-legged Centaurs. But in Roman times they were confused with Fauns, or goat-men who roamed the woods.
The Centaurs were principally savage beasts, half-horse and half-man. Chiron was the exception, a Centaur famous for his virtue and wisdom.
The Dryads were tree-nymphs and had beautiful female shapes. There were also mountain nymphs, wood nymphs, stream nymphs, and sea nymphs, all in female form.
The Gorgons were three hideous dragonish sisters that could change men to stone at a glance. Medusa was the most famous one.
The Sirens were sisters who sat on rocks by the sea and lured sailors to their doom by singing to them.
Helios was the sun god, but he did not play a large part in Greek mythology.
Aeolus was the custodian of the four winds.
Castor and Polydeuces (or Pollux) were famous twins who protected sailors. Polydeuces' brotherly devotion when Castor died made their names a by-word for fraternal affection.
Proteus, the son or attendant of Poseidon, had the ability to prophesy and to change his shape at will.
Triton was the trumpeter of the sea and was depicted blowing a large conch shell.
The Fates were three powerful goddesses who determined the lives of men. Clotho wove the thread of life; Lachesis measured it out; and Atropos cut it off with her scissors of death.
