First you choose whether you want to place the spider or the bat in your glass. 
Paint out the pattern with coloured pencils, e.g. Faber-Castell Colour Grip, and then cut out the animal.

Place the LED tea light in the glass and decorate it with the loosened cotton wool. Use a needle to attach the nylon thread to the animal. For the bat you should attach the thread to both wings, for the spider it is enough to attach it to the body of the spider. Measure the length of the thread so that the animal hangs freely. Glue the other end of the nylon thread into the lid with a little tape.

The spooky Halloween glass is ready.