#mylittlepony - #What is this a crossover episode?

What is this a crossover episode?
https://i.redd.it/b7g51p9ihju11.jpg

Submitted October 26, 2018 at 08:22AM by knightfluttershy
via reddit https://www.reddit.com/r/mylittlepony/comments/9rl5vk/what_is_this_a_crossover_episode/?utm_source=ifttt