Ozyrrandian (AKA Venomfang) is known to the party having been introduced to them when Reidoth the Druid asked for their help in killing VenomFang. Ozyrrandion is a trickster and liar of the first order. It is possible that he never speaks without mixing the truth with lies.
The story of the Chaotic Gold's encounter with Venomfang is told here in Session 6 - Reidoth's Faerie Circle