At the beginning of Act 2 after entering Stinky's Backup Tunnel you will enter an area full of cloning pods, for this trophy you need to damage them 7 times.
In the area select using the
until you have the option of (
) use items with cavern of cloning pods
and then press
to use big gun with cavern of cloning pods
. Repeat this 6 more times and the trophy is yours.