There are usually two ways of killing a normal creature (ones that appear regularly); either throwing all of your Pikmin on it or using the C-Stick
to get them to swarm around it. For the jumping frogs, never throw Pikmin on them or they will all be flattened. When the frog lands, swarm around it. If you have enough Pikmin they will stop it from jumping. For the big snoozing poker-dot bugs, get at least fifty Pikmin, Sneak around to the back of it and keep throwing quickly. It should not have enough time to turn around and gobble any Pikmin. For the square rock that keeps re-planting Pikmin, just get as much Pikmin as possible (seventy recommended) and throw for awhile before he gets too close. Then, run until he stops chasing and start throwing again.