When I saw this my first impression was it is a caterpillar. On close watch I found this spider is making a caterpillar impression by sitting on the both edged of this silk roll. This is on a bonsai ficus tree.
I am sorry for this poor images.
Something reminds me of an Ape-fly larvae, these were found on a compound wall and it looks like human head. The size is about hardly 1 cm or less than that.