Our two travelers have just left Altair-4, a planet long before inhabited by a super-advanced race known as the Krell. The Krell had developed space travel in eons past; and they explored the galaxy gathering specimens of life forms they encountered. The Krell's most ambitious project was a machine which could, controlled by thought alone, create and project solid matter in any form to any location. Having evolved a sophisticated society free of crime, disease, and hostility, they had no way of knowing that their wondrous creation would ultimately destroy them on the eve of its final completion...and later their entire planet as well.
Tigerwolf and Timgee are creations of early Krell experimentation to develop their ultimate machine. Using various animal forms brought from Earth and other planets, they used their early synthesis technology to produce biological combinations.
Essentially brothers, they shared the same human subject as a "father" in their ancestry. They are the only (known) remaining of their kind. Highly intelligent, gentle, and compassionate, both are capable of altering their own forms within certain limits. They are ageless, appearing quite young but they are really very, very old. Only because of their form shifting talents, did they manage to avoid the annihilation which claimed the Krell population.
In the interim after the Krell holocaust and before the first human space travelers discovered Altair-4, they explored the planet looking for others of their kind with no success. Although records indicated other similar creations were produced, no evidence of any of them being still alive was ever found.
Understanding the basics of the Krell technology, they were able to maintain their existence on the planet. For centuries, using the massive amounts of stored information and data in the Krell libraries, they absorbed most of the Krell knowledge and skill. Their continual quest was to find other beings and to escape the loneliness of the place where they dwelled.
Before humans first arrived, they had begun construction of a large inter-stellar craft which would allow them to travel to populated worlds which they knew existed...somewhere.