Looking at the Urza block "living enchantments" reworked as DFC's.
Cards such as Veiled Apparition, Opal Champion etc.

Doing it as a DFC eliminates the need for "If Lurking Jackals is an enchantment..."

It also makes it rather easy to draw the game just by making a Copy Enchantment of the front side; it can't transform and will never stop triggering.

Hmmm... that's an interesting copy enchantment problem. As it is, I was going to suggest changing the name on side 'A'... I think having the same name on side 'B' should be fine, since the game will never recognize side B until the spell is transformed - Thus it is different and the same. But, you know, this is a functional reprint, not the original, so an enchantmanty front name would probably be appropriate. Doubly-so, if we got to mess with the trigger in order to stop easy game draws.

Seems to me, the correct way to word this card would be something like "When ~ enters the battlefield, or When an opponent's life total becomes 10 or less, if an opponent's life total is 10 or less, transform ~." That cuts down on the triggers. The wording is weird, but that's because the first part "When Etb" is aligning with the last part without making an extra sentence "If 10 life or less".

That's a very "errata-y" wording. As in, it'd never get printed like that. It does work around the Copy Enchantment problem quite cleverly though.