Charge atack(Right Click) only hits big targets, it goes trough anything smaller than itself.

While not the best fighters pachy's make decent early travel mounts. Their base speed isn't all to high but using the alternative attack will cause the pachy to charge forwards are decent speeds and dealing a fair amount of torpor to what ever they hit. Pumping movement speed and stamina will have you moving around the map with ease.

Its charge attack is significantly faster than its sprint- I can easily leave my tamed carno in the dust with it.
Just keep in mind that you can't turn, and easily get hung up on even small rock-piles when charging.

Pachycephalosaurus are small, slow dinosaurs that at first glance may seem lacking in the use department. However leveling one of these Cretaceous critters, especially a high level one, in Melee, Stamina and Health can turn them into the ultimate living taming mount only rivaled by a high Melee Mantis equipped with clubs, knocking out Parasaurs, Trikes, Dilos, Raptors, Pteras and more in one or two charge attacks that can down creatures far more quickly and efficiently then the average Beelzebufo or Pulmonoscorpius. Not only that but there eggs can be used to make the preferred kibble of the Paraceratherium. Meaning taming Pachys for eggs is also quite worthwhile