This encounter happened almost a decade ago. My GM made a custom Pathfinder campaign for a party of six, of which we had a fighter, a ranger, a healing oracle, a rogue, a sorcerer, and myself, a human bard named Griffander Rieze (aka, the Griff).
It was second campaign, and my first time playing the class, so I played a pretty standard Bard. I was a skill monkey with some utility spells. In combat, I mostly relied on my whip to trip enemies and my songs to buff the party. I never did any real damage on my own.
Our journey took us deep into a jungle to find a relic found in some lost ruins. The catacombs where full of fluorescent flora that the oracle and sorcerer wanted to study, but a lot of fierce predators for us to contend with as well. We were all third level when we reached this area, and after a lot of tough fights with bad mistakes (most of us were still new players), we found a large set of double doors, still intact.
Inside was a vault with vast amounts of treasure. The relic we came for sat at the end of the room on a pedastel, in front of a giant, six armed statue. I warned the group not to touch anything right away, but the ranger and rogue started grabbing things anyway, this brought the statue to life. Roll for iniative. Nat 20 for the Griff.
Let me pause here and point a couple of things out. My GM had never run a campaign before, so this was his first attempt at doing so, and as such, he wanted to make the final encounter of the scenario pretty epic. A giant construct with 6 attacks and a lot of natural DR should be hard for a ragtag group like ours, at least, you'd think so anyway.
For the first time in the campaign, the Griff was first on the turn order, and his only weapon was a whip, not good for anything armored. I had no means of hurting the thing, and my party was still too scattered for me to start boosting them. I was at a complete loss of what to do, until a strange thought occured to me. A giant construct would probably be pretty hardy, but not very agile. Given Pathfinder mechanics (DnD 3.5 ish), I figured it's reflex might be poor, so I just ran with it. I cast Grease where the thing was standing, and it fell down. The rest of the party then rushed it and started hacking. On it's turn, it tried to stand up. Attack of Opportunity by everyone next to it. It failed and fell down again. On my next turn, I started chanting, better attack and damage. The party continued attacking the downed statue. It tried to stand up again. Attacks of opportunity, and again, it fell down. On my third turn, i smacked it with the whip for no damage and just kept singing. At this point, the GM decided to take a full attack action. Six melee attacks with a penalty (Two weapon fighting) while prone (bigger penalty.) He hit no one. The party finished it off before the round was over.
In all the time I've played Pathfinder with him, this member has always been pretty easy going, and very little gets under his skin. Griff was the first and only time I'd seen him get that way. He was furious and how his epic conclusion played out, so much so that we ended the scenario riding out of the jungle and back to town, and the campaign ended there as well. For years I joked with him about how he should have had a random dragon just swoop in and snatch up a bard for the heck of it, because I knew that character would die if we played another scenario.
I learned two things from that encounter. I learned that you can never fully prepare for what a clever party might do, and I learned to always keep a Grease spell handy if I played a caster, just in case.