There already is an enormous carrion crawler in 4E. This is similar, but they both have threatening reach already and some different powers. The only carrion crawler that lacked threatening reach is the heroic version, both published paragon carrion crawlers have it. The monster vault version does do more damage, but it's not because of threatening reach.Plus it gained threatening reach... it's basically doing triple the damage that it used to do. Which is a good thing, cause its damage was way too low before.