I like him a lot too, honestly he was probably the most fleshed out Predacon in season 1. a lot of episodes had his as some sort of plot point. from the energon storm producing teleports, finding the floating energon mountain and of course the betrayals.
his character arc was complete during the episode double Jeopardy, he finally got command of the darksyde, megatron let him command and he fumbled like they knew he would. all the predacons stepped back and nobody was willing to follow him.
ever since that episode, terrorsaur knew his place and never again tried to betray Megatron or scheme. he actually carried out his orders quite well.