From the Super Mario Wiki
Their names are based off their attack patterns; the giant Chomps relentlessly chase after Yoshi, gnashing through anything in their way. Their appearances in certain levels make backtracking impossible, as they are almost invulnerable and will often eat anything on which Yoshi can land. Eventually, the Chomp Shark chases Yoshi to a platform it cannot eat and breaks its teeth, causing it to tear up in pain (crying) and fall off the screen. Possibly, this enemy can defeated by Superstar Mario ( but only in Super Mario World 2: Yoshi's Island).