Cogsworth naturally has a serious demeanor which is evident in his strict attitude in serving the Beast and ordering the other servants around constantly. However, Cogsworth does mean well and is as good-natured as Lumière is. He is Lumière's best friend and also a rival of sorts. Cogsworth's preference to abide by the Beast's rules often puts a severe strain on his friendship with Lumière, who opts for a more rebellious and care-free personality, but overall, he values his friendship with Lumière and sees him as a brother, demonstrated in the original film (when he saves Lumière from being melted by LeFou, Gaston's henchman) and the midquels
On Christmas night, an old beggar woman came to the castle and asked for shelter. Because of her repulsive appearance, the master of the castle, Prince Adam, turned her away. She then revealed herself to be a beautiful Enchantress, and transformed Prince Adam into a hideous beast, because of his cruel ways. For further punishment, the castle servants were cursed as well, with Cogsworth specifically turning into a clock. If the Beast can't find anyone to love, and love him in return by the time the last petal of an enchanted rose falls, he and the servants will be cursed forever
A few years later, a man named Maurice lost his horse, and needed a place to stay during the brutal winter night. Cogsworth apposed the idea of inviting him in because of the master's rules, but Lumière went ahead and served Maurice anyway, with the other servants following along. Soon enough, the Beast arrives and imprisons Maurice. Cogsworth and Lumière bicker over the event, until they spot a girl, a young maiden named Belle, who is looking for her father, Maurice. She trades places with him as a prisoner, and Cogsworth joins the other servants in their attempt to help Belle and Beast fall in love to break the spell.
As time passed, Belle and the Beast have developed a close relationship. Cogsworth and the others decided to set up a ballroom dance to seal their relationship, but Beast frees her when Maurice becomes stranded in the woods looking for Belle. Cogsworth is the first to hear of Belle's release, and quickly informs the others. With no hope of becoming human, Cogsworth is fed up with the very idea of Belle being able to break the spell. Suddenly, an angry mob invades the castle to kill the Beast.
Cogsworth, and the other servants, battle heroically. Meanwhile, the Beast battled Gaston, the leader of the mob, and an admirer of Belle. He fatally stabs the Beast right before falling off the castle roof top, to his death. Cogsworth, Lumière, and Mrs. Potts, heads to the Beast's side. He dies, but Belle confesses her love before the last petal falls. Beast transforms into Adam once more, and Cogsworth regains his human form, as the head butler as he was before. He is last seen arguing with Lumière about who foretold the fact that Belle would break to spell first.
Cogsworth is witnessing the Beast and Belle relationship together and see they are becoming closer and closer as the day goes by. Belle walks through and seems excited. Cogsworth and the servants have a bad feeling Belle is thinking of Christmas and unfortunately for them they are right.
Cogsworth and the others try their best to change the subject to no avail. Lumière and the others decide to go with it, but Cogsworth does not. While Lumière, Belle and the rest of the castle wishes to do a Christmas celebration without the Beast, Cogsworth out of fear wishes not to join the rest of the group in order to keep the Beast on his good side. He eventually chooses to join them in celebrating Christmas, but warns them to keep quiet so that Beast won't find out.
In the end, Beast finally realizes Christmas is a time to spend with the ones he cares about, and Cogsworth is very happy for him.
On the anniversary of Lumière's first date with Fifi, Lumière grows so nervous to the point that he cleans himself excessively and turns to Belle for advice, by walking with her in the garden and reciting what he plans to say to Fifi to her. Fifi overhears this, and believes that Lumière and Belle are having an affair behind her back. To get back at Lumière, Fifi attempts to seduce Cogsworth, who is apparently not interested.
Cogsworth feels he is losing control over his staff, and demands their respect with harsh treatment. In the meantime, Belle convinces Beast to free the recently-captured bird, and he releases it once its wing is cured, but the bird, still too weak, begins to fall, and Beast rushes to rescue it. In the process, Cogsworth falls from the West Wing balcony and into the garden, but is unhurt, and learns that you cannot demand respect, but you can earn it by giving it.