Who says that the most knowledgable people are adults?
The spy starring in Sabotage, part 2. He may be a double-edged character.
A wizard forced to rule over others, now deceased.
What does a warrior do, if he can not “go on” anymore? Some give up, this one did not.
A great bird so rare (according to some legends only one exists), that with its high intelligence and uniqueness it deserves the status of an NPC.
Aurelius is a hermit slightly different from the others. If you think you can provoke the gods without a punishment, you should meet him.
An environmentally-minded dwarf who opposes the mining of the Kalorsan, the exploitation of goblins in mines and the poisonous, choking fumes from the furnaces of Tr’S-Nang. He is an active member of “Green War”, the dwarfish environmentalist sect, who (though they have renounced their innate dwarfish industrialism) have yet to reach the stage of pacifistic demonstration.
Snowflake is a white-scaled dragon that has gone slightly mad: not only does she like people (not for lunch,that is!), but she wants them to be happy and fine, even if it is not to their liking…
A less-traditional NPC, a magical creature, formerly a tree. Might function as a druid or hermit.
A mighty tree it was, giving shelter to wanderers and many birds, until one night two dragons battled on the sky, right over him. Their motives are unknown, but the loser fell to his death on the tree, and that, broken and burned with the acidic blood of one and the fiery breath of other become what it is now.
Macu spends his time looking for kind and giving people who he rewards in some small way. He does this by disguising himself as a needy person, maybe an injured traveler on the road, or a beggar in a town. The first person that responds kindly to him will receive some assistance in the endeavors, they will find out about the assistance when Macu has finished helping them. If a party member is simply indifferent to Macu then Macu will give the party another chance, in a different situation, if the party is still indifferent then he will leave them alone without interfering with them anymore. If the party is cruel or evil in anyway to Macu then he will punish them is some suitable way that matches their evilness. He will even show himself to them so that they will recognize him and the fact that they were evil/cruel to him.
Schaak is a well built peddler that always seems to have just what is needed at the moment. He is a high powered mage that has given up adventuring and much magic for a more medial, yet rewarding existance.
Fullick is one of three leaders of the Black Hand Rogues Guild. He has been posing as a noble since he joined the guild and it has gone to his head. He acts the part at all times much to the amusement of other guildmembers. Nobody would mock him to his face though since he is a master swordsman trained by the best nobility could afford.
A shaman like man appears out of nowhere and asks if any of the PCs have ever heard of him.
If you want to add a "supernatural" touch to your campaign, define the rules of magic and the universe. Make your players comfortable with those rules. Then your new supernatural creatures must then break those rules.