Tostyn usually liked to wander around the area more than to remain in his lair. It was full of strange curiosities from all around the Realms, like a mummified beholder, a lich's coffin from Tashluta, a green dragon skeleton in a Nimbrali glass armor, many kinds of strange golems and automatons, and many other strange things. In his wanderings, Tostyn sometimes helped adventurers, chased wyverns, destroyed pirate ships, or simply dodged among the storm clouds.
During the Rage of Dragons of 1373 DR, during a trip to the High Forest, Tostyn was attacked by two very young green dragon who'd succumbed to madness. He killed one and injured the other and later retreated to his lair with a large injury.
Tostyn was curious, proud and reckless. He was totally unpredictable, changing ideas at any moment. Sometimes he fought larger dragons only to abandon the fight soon after.
Tostyn's unpredictability made it hard for him to have friend. The only current one was the sorcerer pseudodragon Laeralyn, whom he saved from the black dragon Cheleen in the High Moor. During the Rage, unknown to him, Tostyn gained an enemy in Chloracridara, who wanted vengeance for the death of one of her offspring.
- Ed Greenwood (February 1999). “Wyrms of the North: Tostyn Alaerthmaugh”. In Dave Gross ed. Dragon #256 (TSR, Inc.), pp. 72–76.