Stronger

Stronger (ストロンガー, Sutorongā) is the name of the horse that Doc Q rides on. Because Doc Q is seemingly always sick, he rides on Stronger all the time. However, Stronger is just as sick as he is.

Mock Town
Stronger is simply shown to carry his rider, Doc Q, throughout their appearances in Mock Town.

Banaro Island
Stronger was once again carrying his sick master during the raid on the Blackbeard Pirates' Banaro Island. When Portgas D. Ace attacked them, Stronger and Doc Q fell while running to avoid their captain's retaliation, and was picked up by fellow crew members Auger and Burgess. They all watched as Blackbeard defeat Ace in a safe distance.

Impel Down
During the Blackbeard Pirates' attack on the Great Jail, Impel Down, Stronger is once again carrying the sickly Doc Q. After an exchange of words between Blackbeard and Monkey D. Luffy, Stronger was poisoned along with the rest of the crew by Magellan's Hydra technique. Later, the whole crew is saved by an antidote from former Chief Guard Shiryuu, who accepts Blackbeard's offer and joins their crew.