Say no more to boring basic tee for boys.
In this tutorial, I use Issie Tee with color blocking option with Y piece only. You may purchase the pattern here. But you can use any pattern for this appliqué.
Place the X piece pattern on the right side of the fabric and mark on the fabric using washable pen.
Then, align the armscye of the back bodice with the armscye of the front bodice that has been mark on the fabric.
Then draw the bottom line of the bodice using the back bodice pattern piece.
By using ruler, draw a straight line as shown below.
Then place the appliqué pattern piece on the right side of the fabric. I used cotton lycra for this appliqué. It is easier and nicer to use any knit fabric since knits don’t fray. So you just can sew a straight stitch on top of the appliqué. Download the dinosaur appliqué pattern here.
I prefer to stabilize the appliqué pattern piece before sewing it to the bodice. It is recommended to use fusible knit interfacing for this step. Iron it to the wrong side of the fabric.
Place the appliqué on the right side of the bodice. Pin it and sew. You can you triple straight stitches on your portable sewing machine or sew double straight stitches using your sewing machine. Then you can also add the eye and mouth for this dino. 
DONE!!!