Is it easy to transfer between the Big 4? I found out PWC has consulting and I want to do that instead of accounting
It's possible, and as far as I know, it's encouraged, but it's not "easy" per se. You will still need to be doing reasonably well in your current role and be able to offer something to the division you want to move to. Advisory is a popular target and some of my friends have transferred over the years, but depending on the role, you may still need to do interviews and possibly even testing because not all roles are open to all levels (e.g. infrastructure consulting may require a senior grade or higher).
Note that all the Big 4 have some form of advisory or consultancy practice, and each of them is very diversified in what they offer... some offer the basic and common performance improvement, liquidation/insolvency, restructuring, m&a/transaction services, valuations, economics consultancy, etc... whilst others might be more specific and exotic such as health consulting, environmental consulting, IT project implementation, etc... there's a lot of variation. The challenge is proving to the guys in the respective team that you have something which can be useful to them whether it's experience, skills, client relationships, or just a strong reputation for getting things done well.
Also worth mentioning that at trainee level, most firms won't accept anyone without at least a university degree into advisory/consultancy although every now and then there is an exception or two. Usually people move into these areas once they are CA qualified.