With just a few readily available materials, you can make a cool cow costume for Halloween.
Steps

Step 1. Draw some curved lines on a piece of black felt

Step 2. Cut the pieces and put some spray glue on one side

Step 3. Glue them to sweatpants and a t-shirt to represent cow spots

Step 4. Cut a piece of string to make the tail
Tear off one end to make the tail more realistic.

Step 5. Inflate the glove and close it tightly
It will be the udder of the cow.

Step 6. Use the white thread to tie both the udders and the tail to the cow's waist

Step 7. Now attach the horns to the head
You can either use a hat from a Viking costume that has horns (colored black) or make your own from paper. If you choose the latter option, make cone shapes and glue them in the right place. Then color the horns black, put on an elastic band and wear them!

Step 8. Finished
Advice
- If it seems necessary, you could fill the shirt with a light towel or cotton to mimic the thickness of cows. It's especially good if the costume is for someone who doesn't care about looking fatter, even if it's just for Halloween.
- You can even add a cowbell if you want!