Triggers on Slave database (in the context of replication) for auditing purpose in MySQL
@parag Yes you can create triggers on the slave which won't be replicated. The only issue I see is if you're Master fails and you promote your slave to master you will need to keep track of what changes need to be applied to the new slave and what changes need to be applied to the newly promoted master.
If I'm not mistaken you can create the triggers on the master so that they can be replicated and then disable them and just enable them on your slave.  That way all your environments will have the triggers but only enabled on one slave.

Or, so you can avoid managing details like that, which can become overwhelming, you can make the slave, the master of another slave which will do the auditing and only have the triggers on that subsystem.

Thanks
John