[Garrabutártulo]

mmm I think I should post it here, but I'm not sure.

I'm trying to get a chansey with seismic toss. I looked on the internet and some website says I need a tutor. I went to battle frontier and none of the tutors can teach seismic toss.
Is it an egg move or something?

In short: how do I get seismic toss on a chansey?