import re

contents = '''
  var cool_spirit_animals = {
    'Abel': 'unicorn',
    'Bob': 'lion'
  };

  var spirit_plants = {
    'Cain': 'venus fly trap'
  };

  var stupid_spirit_animals = {
    'Dan': 'lamprey'
  };

  var spirit_vampires = {
    'Emily': 'Buffy',
    'Fred': 'Dracula'
  };
'''
def repl(m):
	return re.sub(r"'(\w+)':", r"'\1 Smith':", m.group())
	
my_regex = r'spirit_animals\s*=\s*\{[^}]*(?:}(?!;(?:$|\n))[^}]*)*};(?:$|\n)'
print re.sub(my_regex, repl, contents)