Do not type the word option.  For exampe, the next two are the same 
MakeSnow("snow",1);
-or-
MakeSnow("snow","animate");

option is 0  or 'noanimate' if you do not want animation
option is 1 or 'animate  for animation 
(See below for other option values)

  <script>window.onload= MakeSnow("snow",option);</script>

  <script>window.onload= MakeSnow("snowalt",option);</script>

  <script>window.onload= MakeSnow("leaf",option);</script>

  <script>window.onload= MakeSnow("ornament",option);</script>

  <script>window.onload= MakeSnow("balloon",option;</script>

  <script>window.onload= MakeSnow("firework",option);</script>

  <script>window.onload= MakeSnow("valentine",option);</script>

  <script>window.onload= MakeSnow("saintpatrick",option);</script>

  <script>window.onload= MakeSnow("halloween",option);</script>

  <script>window.onload= MakeSnow("football",option);</script>

These are the predefined Image displays:

"snow"  shows snow images
"snowalt"  shows alternative snow images (more variation)
"snow*" shows character *+. snow
"leaf"    shows falling leaf images
"ornament" shows falling ornaments
"balloon" shows rising balloons
"firework" shows rising fireworks
"valentine" shows falling hearts and lips
"saintpatrick" shows falling hats and shamrocks
"halloween" shows falling bats
"football" shows falling football things

myimages are optional array images or text lines to display - from 1 to as many as desired. - see code at end

You can put multiple choices in Image. For example 

MakeSnow("snow leaf","animate");  // select BOTH snow and leaf images

You can vary the number of elements, the speed, the maximum size, the minimum size, fonts and text colors. However, they are all optional.  See example below that shows them all being used for this page.

Additional Animation Values (the default is a full screen display - except for phones - see phone option)

The display can be limited to just the SIDES of the page in Option and additional options
left - display images on the left side
right- display images on the right side
both- display images on both sides
phone - display on a phone - default is no display on a phone (android or iPhone)

Script that is always required before one of the following is entered below
<script src="https://www.classcreator.com/000/7/7/0/13077/userfiles/file/snow/snow-and-more.js"></script>

Option below has two formats, only numbers 0 and 1 and characters enclosed in quotes.
The character format has additional choices where to display the images.

animate is 0 if you do not want animation and animate is 1 if you do want animation (Do not type animate)
             -OR-
"animate" same as 1, "noanimate" same as 0

The first example shows the two formats that are identical. First one uses a number, second one text format

<script>window.onload= MakeSnow("snow",1);</script>                  // generates snow
<script>window.onload= MakeSnow("snow","animate");</script>   // generates snow

<script>window.onload= MakeSnow("snowalt",Option);</script>   // generates snow alternative images

<script>window.onload= MakeSnow("snow*",Option);</script>      // generates character snow

<script>window.onload= MakeSnow("leaf",Option);</script>           // generates leaves

<script>window.onload= MakeSnow("ornament",Option);</script> // generates ornaments

<script>window.onload= MakeSnow("balloon",Option);</script>    // generates balloons

<script>window.onload= MakeSnow("firework",Option);</script>  // generates fireworks

<script>window.onload= MakeSnow("valentine",Option);</script>  // generates valentine

<script>window.onload= MakeSnow("saintpatrick",Option);</script>  // generates saintpatricks

<script>window.onload= MakeSnow("halloween",Option);</script>  // generates halloween

<script>window.onload= MakeSnow("football",Option);</script>     // generates football