Lizardmen are not a playable race in AoW3. They used to be playable in AoW1. The historical Lizardmen unit lineup can be found on the Age of Wonders 1 Heaven site: http://aow.heavengames.com/units/unitstats_lizard_ts.shtml
General: Lizardmen are a savage race of reptilian humanoids. Lizardmen are covered in scales and vary in color from deep green to a lighter brown-green. Lizardmen prefer to live near large bodies of water or swamps, but can thrive in nearly any climate except the cold North.
Society: Lizardmen society is governed almost entirely by strength and brute force. All Lizardmen answer to a single king, selected by his ability to defeat the current king in hand-to-hand combat. One’s status in determined almost entirely at or before birth. Potential Heroes and kings usually have some discerning characteristic present on their eggs, or on their bodies once hatched. A spotted egg often forecasts the birth of a shaman or one with magical ability. Since magic is viewed with distrust in Lizardmen society, a close eye is kept on those few shamans with the ability to wield magical powers. Still, they are typically given important roles, such as becoming the king’s advisors or the town’s healers.
Combat: In combat, Lizardmen fight in unorganized groups, relying heavily on frontal assaults. Lizardmen are extremely aggressive and prefer melee combat to missile attacks. One of their most devastating tactics is to cross bodies of water and launch surprise attacks on unsuspecting cities. They are able to do so with full siege weaponry, as they employ specially constructed ballistas and catapults mounted atop giant turtles.
(c) Age of Wonders Manual