Warlock Patron: The Elder Wyrm [PEACH]

[Amnoriath]

It is interesting that you made a warlock sub-class without bonus spells but you effectively gave it to them as your 10th level feature but your 1st and 14th level features are a way too much.
1. Your breath weapon scales far too much giving you an effective at will Cone of Cold coming from a Evocationist Wizard. I am assuming your save DC is just a gaffe because there is no way anything but epic level monsters can even make the save. The 5e save is 8+prof. bonus+ability score modifier, just use your spell save DC.
2. Your 14th level just needs to be redone or changed entirely. Wild Shape is already controversial because it acts like temporary hit points. Using CR 1 creatures may be pushing it but reasonable, but an Adult Dragon and eventually an Ancient Dragon you might as well as be immortal as well as decimating the field single-handedly. The feature would be dubious for a once per long rest ability.
3. There is no Entangled condition, only Restrained but that is way too good for it being automatic.
4. One of the great things about the Dragonfire Adept wasn't just the breath weapon but its series of interesting utility. I am a little saddened that you didn't at least attempt to touch on them in bonus spells.