I could talk about all of them, anonymous, but I suppose the most appropriate place to start with the ultra beasts would be with the first one ever documented:
Nihilego
The Parasite Pokémon
Type: Rock/Poison
Official Registration #: 793
Entry: One of the Ultra Beasts, or strange pokémon that had appeared from another dimension. This jellyfish-like pokémon possesses strange and not well-understood powers, including the ability to teleport, open portals, and influence the human mind. Those who were exposed to this creature’s neurotoxins have reported erratic and often fervent or obsessive behavior, usually culminating in extraordinary feats for the sake of ripping apart the space-time continuum in the name of science and pokémon. Incidentally, the above-mentioned symptoms also describe the effects of hard liquor on the author, which also incidentally is a state that led to the creation of the Time Capsule, so if there are no objections, the author would like to propose an experiment involving himself, a nihilego, and a bottle of whiskey.
I have objections. I have a lot of objections to this plan. —LH
The Pokédex According to Bill 