Horologium

Horologium, "The Clock", is a one of Silver Keys' Celestial Spirit that is owned by Lucy Heartfilia.

Macao arc
Lucy summons Horologium to keep her sheltered on the snowy mountain where Macao was last seen.

Fighting Festival arc
While being battered by Bixlow's dolls, Loke told Lucy to summon Horologium. However, she then tells him that she is unable to do so, since Bixlow's dolls stole her keys.

Edolas arc
Lucy explains to Natsu, that Horologium passed through the gate and hid her away in an alternate space, telling her that he had sensed a disturbance in space.

Magic and Abilities
He keeps people safe within his clock body and he narrates for those inside him. He can be used in both non-combative and combative situations. Lucy uses him as shelter and transport when traveling in snowy area. In combat, he can protect the person inside him with his hard-wooden body. However, Horologium does not seem to have combative moves. He is also mostly on a time limit whenever he is out and will transport back to the Spirit World once the time is up, leaving his occupant behind, regardless of any danger they may be in.

Trivia

 * Lucy's quote when summoning him is: "Open a Gate of the Clock! Horologium!", as seen in the Chapter 2, when she first summons him.
 * Lucy often rides inside him when hiding, or becomes too tired to walk.
 * As the glass of Horologium's body seems to be sound proof, he says what the person inside him is saying so that people on the outside can hear them. He always ends in saying 'she/he says' (to moshite arimasu) whenever doing this.
 * If Horologium's glass is soundproof, it is unknown how Lucy is able to hear others when she replies to something they say.
 * It is possible that Horologium has telepathic power with the owner/rider, as he can talk in Lucy's place when she is riding him, while Lucy herself seems to say nothing.
 * He always keeps his eyes closed, and his face expressionless, even though he vocally depicts out the emotion his rider is feeling.
 * During the events of Edolas, Horologuim summoned himself to shelter Lucy from the effects of Anima. This is the first time he has ever done so.
 * Even though he always keeps himself on a time limit, it is currently unknown how long he kept Lucy with him in the alternate space. So, it is possible that he stayed longer than his contract defines.
 * "Horologium" may mean in latin: a clock; a sundial or  water  -clock