Galoob made large versions of the Flex and Animal where the tires reacted. If the Flex ran into an obstacle, the hubs moved in and made the tires balloon out so it could go over it
The Animal had 'hidden' claws that would come out (3 per each tire) when it encountered difficulty. People confuse the Animal with the Claw which on the latter, the tires would split open revealing claws and extend the overall size of the tire to clear an obstacle.
Both the Animal and the Claw can be seen in this commercial compilation video
( it also features a low quality of Tomy's Monster Machine that you might like)