How can I load the image overlapping-ly to create animation from spride sheet?

Question

I am having trouble loading the image from sprite sheet overlapping-ly to create an animation for my character in a fighting game. [enter image description here](https://i.stack.imgur.com/E5Uh8.png)

The following are the function for loading the image and the animation list. I will also attach my sprite sheets as well. Please let me know if you want the entire file of code.

    def load_images(self, sprite_sheet, animation_steps):
        animation_list = []
        for y, animation in enumerate(animation_steps):
            temp_img_list = []
            for x in range(animation):
                temp_img = sprite_sheet.subsurface(x * self.size, y * self.size, self.size, self.size)
                scaled_img = pygame.transform.scale(temp_img, (self.size * self.image_scale, self.size * self.image_scale))
                temp_img_list.append(scaled_img)
            animation_list.append(temp_img_list)
        return animation_list


    def update_animation(self):
        animation_cooldown = 500
        self.image = self.animation_list[self.action][self.frame_index]
        # Check if time has passed for new update
        if pygame.time.get_ticks() - self.update_time > animation_cooldown:
            self.frame_index += 1
            self.update_time = pygame.time.get_ticks()
        # Check if the frame index has finished to the end of the screen
        if self.frame_index >= len(self.animation_list[self.action]):
            self.frame_index = 0

And the following is how I loaded in the main.py file.

# define fighter variable
CAT_SIZE = 40
CAT_SCALE = 5
CAT_OFFSET = [17, 15]
CAT_DATA = [CAT_SIZE, CAT_SCALE, CAT_OFFSET]
GIRLGUN_SIZE = 50
GIRLGUN_SCALE = 5
GIRLGUN_OFFSET = [20, 17]
GIRLGUN_DATA = [GIRLGUN_SIZE, GIRLGUN_SCALE, GIRLGUN_OFFSET]

# Uploading the background image
background_image = pygame.image.load("assets/backgrounds/university_background.jpg").convert_alpha()

# loading the character
cat_sheet = pygame.image.load("assets/characters/cat.png").convert_alpha()
girlgun_sheet = pygame.image.load("assets/characters/girlgun_bg.png").convert_alpha()

# Define number of steps in each animation
CAT_ANIMATION_STEPS = [10, 10, 10, 10, 10, 10]
GIRLGUN_ANIMATION_STEPS = [5, 5, 8, 8, 5, 5, 8, 8]

while running:
    clock.tick(FPS)

    draw_bg()

    # show the player's health
    draw_health_bar(player1.health, 20, 20)
    draw_health_bar(player2.health, 580, 20)

    # move player
    player1.move(SCREEN_WIDTH, SCREEN_HEIGHT, screen, player2)
    # player2.move(SCREEN_WIDTH, SCREEN_HEIGHT, screen, player1)

    # update animation
    player1.update_animation()
    player2.update_animation()

    # draw player
    player1.draw(screen)
    player2.draw(screen)