Wulf Ratbane
Adventurer
But for the part about underground roots- which is a judgment call by the DM- I'd say Entangle is pretty well designed.
(I'd allow the roots, BTW.)
In areas where there are no roots, the spell is not prepared.
In areas where there are roots, the spell is a powerhouse.
It would be functionally similar, from a poor design standpoint, to a theoretical Slay Black Dragon Named Bob spell.
Now having said all that, I don't have a problem with entangle, and I'm equally happy to posit underground roots as I am the animals that show up at the unlikeliest of times in response to the druid's call.