I've been playing quite a bit the past few days and i still have yet to find one of those evolution walls that unlock the crusher? it couldve really helped a few times, is there like some sort of parameter or amount of points needed to use him?
Once a set amount of time has passed you can approach a hived wall and "morph" into the Xeno Crusher. As for the locations go to a private match and try to look for them. Sometimes I can't find them either, but there's not that many maps so it won't take long to memorize.
(https://www.avpgalaxy.net/forum/proxy.php?request=http%3A%2F%2Fimg832.imageshack.us%2Fimg832%2F6838%2Fimagekqz.jpg&hash=04f4edb6379eeb8d1465c91497439a8098d5dc41)