Kalan was a Rovidian street-urchin who assisted the War Doctor.
He called the Sontarans moonheads. He was searching through the wreckage of Dalek spaceships for useful stuff when he saw the crash of the ship the Doctor was using to pass the blockade. He showed the Doctor where the Sontaran's had put Ollistra in order to get them off his planet. After the Doctor had trapped Fesk with him, the other Sontarans used his life as a bargaining chip to get Fesk out. After the Daleks started to attack, he found a way out of the citadel to the Battle TARDIS. (AUDIO: The Eternity Cage)
He tried to save the Doctor when Heleyna pushed him out of the TARDIS. He was delighted that once the Sontarans had gone his people started to attack the Daleks to save the Time Lords. With Ollistra's help he managed to stop Heleyna from getting taken to the Daleks. He tried to stopped Heleyna from staying behind in the disintegrating Eye of Harmony chamber and was shot by a Dalek but wasn't mortally wounded. He started hearing his father's voice due to his exposure to the Time Vortex. He died soon after the TARDIS crashed into normal space. (AUDIO: Eye of Harmony)