Also you may end up buying more than one. Not just because Basschat does that to a person, but because they have different characters. Don't be put off if the first one doesn't do it for you.
I started with the POG, widely regarded as a great pedal, and I love EHX pedals, but it wasn't what I was looking for. I went through other great stuff until finding a little Valeton octaver produced the sound I wanted.
Also the pitch shift on the Zoom multistomp does a fantastic octave down while the digitech ricochet produces a lovely high octave.
Dive in and have fun.