Not really image based, but a thinker.
Tyranitar is known to rampage around, smash mountains around, and generally disrupt the landscape to the extent that maps are worthless in areas where they live.
Aggron, on the other hand, claims an area as its territory, and works to restore and build up the ecosystem where it settles down, and drives off anything that disturbs its work; it also just so happens that while Aggron is weak to Larvitar and Pupatar, harmless residents, it has only an advantage against Tyranitar, the destroyer of ecosystems it might have to drive off.
Tyranitar and Aggron work in tandem to constantly reshape and cycle the landscape of pokemon. Because of the work of these two species, the Pokemon world realistically functions as one defined by cataclysmic shifts, rather then geologic ones.
Reinforcing this, Aggron and Tyranitar were considered exclusive counterparts, with Tyranitar, the destroyer, appearing in Y, and Aggron, the rejuvenator, appearing in X. Keep in mind, Tyranitar is a Psuedo, Aggron is not, and they were considered counterparts, even though Grachomp was getting a Mega as well, and would have been a better exclusivity partner to Tyranitar.
