A metal slug like thing

[acefirebat]

Hey im making a map based on the book "The Maze Runner" by J. Dashner. and in the book there are like these mechanical slugs that they call Grievers with spikes on there backs and like 3 hand probes that they attack with. and when they move the like take everything into there bodys and roll around. im not sure if it would be possable to make two diffrent walk things so that he could be like slithering around and attacking and then another one for just rolling. it would help alot if you read the book but i think thats what they look like. if anyone can do this it would be a great help.