A bobble is a fancy stitch made by knitting with several increases on a stitch, then decreasing to a stitch. I explain here a bobble of 5 stitches.
1. Knit 1 st and without pulling it off the left needle.
2. Knit a yarn over.
3. Knit 1 st again in the same stitch.
4. Repeat the step 2 and 3. You now have 5 sts.
5. Turn, P5. Turn, K5. Turn, P5.
6. Next right side row, begin the decrease. Slip the first 3 sts as knit them together on the right needle.
7. Then knit next 2 sts together.
8. pass the 3 slipped sts one by one over the knitted st.
9. Voila, the bobble is done!