The first two things I see:

• maybe a typo?

  images = element.find_elements_by_class_name("catagory")

  category instead?

• if you want to retrieve a unique element, you have to use 'find_element_by_class':

  There are various strategies to locate elements in a page. You can use the most appropriate one for your case. Selenium provides the following method to locate elements in a page:

   find_element
  

  To find multiple elements (these methods will return a list):

   find_elements
  

  If you want to locate several elements with the same attribute replace find_element with find_elements.