It’s Friday, and you know what that means — time for our weekly dose of cat videos culled from YouTube. Today we have a cat descending a staircase, an amazing back-flip jumper, a Siamese sneak attack, a massage given to a dog, and a kitty and puppy at play. For these and other videos, please check out the DogTimeTV channel.

The sinking of the R.M.S. Titanic is widely regarded as one of the most tragic events of the 20th century.…