Learn to Speak Dog with the Hell Hounds, and Skele-dogs (Grim's Days)

Learn to Speak Dog with Hell Hounds and Skele-dogs was a video uploded by Cartoon Network to their YouTube channel. It also aired during their halloween event in television, as a special one- off, and was considered a short. The runtime for the minisode was no longer than 3 minutes, but had an extended version near the end of Halloween.

Synopsis
We head back to the Shadow Car, this time for- speaking to dogs?! What awaits the return to  this Car? A ghost, an entity not seen? Or is it just- dogs?! I know dogs could be tough to carry around even in Train Cars, but in this train car the dogs are undead. Well, except for one found by Grim the Reaper.

Behind-the-Scenes
The short was only intended to be a video in Cartoon Network's channel, but it grew more as a halloween special, considering next year Infinity Train moved as a streaming service, instead of being at it's home. It is also part of a trilogy of shorts, starting with 'Learn to Speak French wih the Cat'.

Trivia

 * Cartoon Network has released numerous outside-show content of Infinity Train, not including train tales, as it is based of the characters in the show, and is in the show's format.
 * This short, though, is the only one aired for Halloween.
 * The third short is said to be longer than per usual, and about christmas, going back to the snow car.
 * Though the first short is more of a compilation, not new content, the second and possibly even the third are all animated, similar to Train Tales, but shorter.
 * Another noted difference is that they are only supervised by Owen Dennis, and the crew is the one that animated the short.