a yellow cocoon! its not surprising, it could be a silk worm cocoon are you surprised, silkworm cocoon's can be yellow AND white, also there's two kinds, I talked about the first one, it could be the other kind too!
The caterpillar makes a cocoon to complete the metamorphosis and turn in to a moth, butterflies make a chrysalis.
Cocoon
Cocoon
After the caterpillar spun its cocoon, it transformed into a butterfly.
cocoon
a caterpillar forms from a cocoon
cocoon.
A cocoon.
IF you mean 'cocoon' it's where the caterpillar changes into a butterfly (or moth) The cocoon protects the developing caterpillar while it goes through metamorphosis.
it will most likely not survive, to play it safe dont do it!
caterpillar
It's a caterpillar spinning into a cocoon