What makes this card truly unprecedented is the lack of an until end of turn clause, the transformation is permanent
They're not really combative and most spells don't make sense as being train-themed
You need to be sure that being guaranteed to hurt your chances is still better than cutting one of the cards you're thinking about
We could also supplement this in a deck that makes use of enchantment synergies with cards such as Ethereal Armor or Eidolon of Countless Battles
Speaking of prowess, the creature side of Elusive Otter has that keyword ability, and it also cant be blocked by creatures with power less than its power, making for an elegant and highly synergistic card, especially when paired with more Otters
Sorry Skithiryx, the Blight Dragon, you cant regenerate through this one