The Brainbench Perl tests I've taken were a joke, frankly. I'm glad I took them just for sake of curiosity and not because a job depended on them. The certificates look pretty nice.

I took some other company's Perl test as part of the application for a job a few years ago. I don't remember the name of it, but the questions mostly were much more sane.

There are, so far as I am aware, no Perl tests endorsed by Larry, The Perl Foundation, or any publisher or author of the better-known books on Perl.

I'm not sure a certification test meant to be taken in the usual time frame for those sorts of things could even come close to measuring more than glancing Perl knowledge. The language is just too large, complex, and flexible to cover in half an hour or even four hours. All one can be sure of realistically is that a decent test will trip up those who are dishonest about knowing the very basics of the language. Anything past that would require a very good test and perhaps some wishful thinking.