This creature is called a Kartack. It's deadly can opener shaped mouth is it's primary hunting method.
Whatever world it is from it's prey are larger slower moving creatures that I would say resemble a hippo or elephant. The Kartack can charge it's prey with short bursts of speed. It's legs are not designed for speed. They are designed to pivot the head and neck up with tremendous force. The idea for the Kartack is to charge from the side connecting with the ribs or pelvis. It lowers it's head like a bull and when in position rams it's head upwards jabbing it's lower hooked horn in-between ribs. Then It immediately thrusts it's head back down connecting the top hooked horn around more ribs. Thus locking the the prey from going anywhere. From there it uses it's powerful front legs and neck to more or less rip out the side of the rib cage killing or injuring the prey enough to resist fighting. From there the Kartack has easy access to the innards for a meal.
This is a sketch I started a few years ago for a character/creature design class with the intentions of taking it to a full rendered picture. I finally came across the sketch last week, scanned it in and finished it. It took roughly 4 or 5 hours to complete scattered over a weeks time. It was done in photoshop with a wacom tablet.