Trying to ensure that one item spawns at a time

Hi, I’m trying to say when an enemy disappear from the screen it will move from 1 array to the next while maintaining the previous shape it has already drew. However, whenever I run the code it seems to draw all the arrays for me.
Can someone help me trouble shoot this and tell me what to add or change thx.

float [][] Mpos = new float [4][2];
if (enemyexit == true) {
    for (int i = 0; i< Mpos.length; i++) {
      for (int j =0; j<Mpos[i].length; j++) {
        Mpos[0][0]=  random(120, 150);
        Mpos[0][1]=  random(-150, 120);
        Mpos[1][0]=  random(-120, -150);
        Mpos[1][1]=  random(-150, 120);
        Mpos[2][0]=  random(-150, 150);
        Mpos[2][1]=  random(-120, -150);
        Mpos[3][0]=  random(-150, 150);
        Mpos[3][1]=  random(100, 120);
      minicreature(mouseX+Mpos[i][0], mouseY+Mpos[i][1]);

What next? I just see one double array receiving random values every enemyexit.

I meant from the first values in the array to the next value in the same array

I understand, but like I said you are filling all indexes in the double array with random values, not transferring anything.

Actually I want to values to be used in my mini creature x and y position