Tiktaq'to may join units of Terradon Riders, but no other units. Tiktaq'to, and any unit he leads, may choose not to deploy on the table at the beginning of the battle. Instead, at the start of each friendly turn (starting from Turn 2), roll a D6 to see whether Tiktag'to arrives:

In the Remaining Moves phase of the turn when he arrives, Tiktaq'to, and any unit he leads, can enter the battlefield from any table edge. They are treated exactly as if they were re-entering play the turn after they had pursued an enemy off the table, and therefore they may not charge that turn.