There's a smattering of cards that specifically interact with otters or make otters, and many of them are nice, efficient cards, even for a spellslinger deck with inexplicably few otters: Lilypad Village Valley Floodcaller Harnesser of Storms Otterball Antics Pearl of Wisdom Rockface Village Splash Portal Stormchaser's Talent Valley Flamecaller All of this adds up to an Izzet Prowess deck that features otters, which is awesome
You can only use 1 "Machina Fabbery Unit" per turn, and only once that turn
Id strongly recommend picking up at least one when you can, as it will likely be sought after for a long time
Arven (Paldean Wonders) is not available in Rare Packs
If this card on the field is destroyed by battle or card effect: You can add 1 "Polymerization" from your Deck to your hand, and if you do, add 1 other "Ancient Gear" monster from your GY to your hand
This card is on the list because, most of the time, youre getting a 2/2 haste creature that, if it dies, deals damage to your opponent