Pathfinder has a giant-focused Adventure Path called Giantslayer. Let's take a look.
|Pathfinder chapter headings sell adventure and peril better than WotC covers. Pure facts.
BATTLE of BLOODMARCH HILL
In the town of Trunau, the PCs start out investigating a murder, but soon find that there are orcs looking for a giant's tomb. The town is situated in human lands near orc lands, so there are plenty of half-orc citizens of the town, and the adventure plays on this tension. Eventually the hill giant chieftain Grenseldek leads her orcs in a siege of the town. The siege includes a subsystem whereby PCs gain "resolve points" which help determine the larger fate of the town based on the PC actions. At the end of the siege, the PCs face Crusher, the cave giant ally of the orcish horde. CRUSHER KNOWS ONLY PAIN.
The orcs seek, and have located during the siege, the subterranean tomb of an old hill giant hero. That's the goal - to get in there. So of course the PCs chase 'em in! Obviously things are timed such that you don't catch up to the orcs until the final chamber, duh. Within the tomb the PCs will find half of a map to a great giantslayer's tomb, and some pretty badass armor relative to the level of the PCs.
Minimal actual giant content in the adventure part of this one, which is understandable given the level range. There are of course lore details about giants in Golarion, some feats and spells.
THE HILL GIANT'S PLEDGE
In part two, the PCs head up the river to the marsh to find the rest of the orc/giant problem. There are some interesting river encounters herein, and more of the "good orcs and bad orcs" theme. Finally you arrive at the Ghostlight Marsh (and be aware, marsh giants are the next step in the PF giant CR ladder). So there's a marsh giant, ogres, more orcs, and some swamp hazards, before attacking/infiltrating the orcish fortress. The place is crawling with orcs and a couple giants, and the chapel has a good-guy ghost of a cleric in it, which is probably a nice break from all the orcs.
So it turns out that Grenseldek, the leader of this band of hill giants, ogres, and orcs, has attempted to offer her hand in matrimony to a storm giant (more about him later in the AP, surely). Grenseldek has assembled a mighty dowry of treasure here, but her bid to be queen has been cruelly rebuffed by the storm tyrant, who is of course far above her station. Defeating Grenseldek not only protects the town of Trunau, but gets the PCs the other half of the map to the giantslayer's tomb. And knowledge that this storm giant tyrant guy is out there, of course.
FORGE OF THE GIANT GOD
Volstus the Storm Tyrant is gathering an army in a hidden valley in the Mindspin Mountains. But nearer to Trunau is the dwarf giantslayer tomb, which probably contains special steel that won the last war against the giants. Obviously we need to use our map and go there!
The small tomb itself is occupied by some rather nasty ettercaps, including the corrupted dwarf/ettercap monstrosity "Stilgrit, the Mother of Spiders", who is as gross as you'd expect. This map and encounters might be worth stealing just as a brilliant ettercap lair. The tomb-proper also features the accursed murderer who killed the giantslayer in the first place, and a couple interesting magic items.
When the PCs get to the valley, there are lots of little places to explore and encounters, including both the non-giant (perytons! leucrotta!) and the giant (hill giants, some giant wights). Since the valley was once home to a giant civilization, it is littered with ruined shrines and the like. Eventually they get to the end of the valley with the Cathedral where all the giants are gathering. Sneaking past all the encamped ogres, ettins, and giants will be a challenge, but once you've done so, you can get into the Cathedral itself, deal with its guardians, and confront the stone giant Urathash, who's in charge here. Oh, and Urathash has a dragon.
The gimmick here is that once PCs have access to the forge in the cathedral, they can return here to use the forge's magic powers - one of which is, in conjunction with the magic hammer from the first book, to resize giant-sized arms and armor, even magical ones. Like that nasty weapon the boss of the next module used? Bring it here and shrink it so your barbarian can use it. It's a neat idea - one that would play out more in a less story-driven campaign I suspect. How often do we expect PCs to come back here?
The bestiary in this one has some neat stuff, like mongrel giants (ie giants of one type with some ancestry of another), and the living cave painting, which sounds very cool and maybe now that I've said it you don't actually need stats for it. The page of mongrel giant variants is worth looking at to spice up your Storm King's Thunder or Against the Giants.
|Cyclops eyebeam goes pew pew
ICE TOMB OF THE GIANT QUEEN
Undead frost giant queen. There's your hook. Skirkatla is one of the Storm Tyrant's lieutenants, and this adventure is her chance to shine - and maybe betray the Tyrant.
The PCs head to the frost giant village and their job there is to disperse the forces by means of sabotage, not direct combat. Pathfinder being Pathfinder, we now have some mechanics for earning Sabotage Points (which are good, and undermine the giant army) but also Outrage Points, which are bad because it means you're convincing the giants they're under direct attack. The higher the Outrage meter goes, the more vigilant and trigger-happy the giants get, increasing patrols and scouts, adding wicked undead stuff to night patrols, and so forth. It's a conceit, but an interesting one, and I wonder how well it works in play. It reminds me of the Chaos index in Hill Cantons material.
We get a map and description of an entire frost giant town and its inhabitants (possibly worth stealing); what the PCs do next is up to them. This is one of those setups when you wonder what a stealth-heavy party would do with it - sneaking invisibly into the meadhall, that sort of thing. Plenty of giants (not just frost) and other things to tangle with here, including an immense wickerman. If the heroes are successful in getting enough giants to abandon the village, they'll have access to Skirkatla's Crypt.
The crypt is a decent-sized one-level dungeon! What's in here? Some frost giants, sure, but also some nasty necromantic creations - an icy mammoth and a huge centauroid headless horseman among them. Ghosts, undead frost giants -- this is reminding me of Crypt of the Death Giants. Push through the whole thing and defeat Skirkatla and her tomb giant minions, and you walk out with some nice treasure and a map to the fire giants. Tradition!
ANVIL OF FIRE
Speaking of tradition, the fire giants are in a subterranean complex beneath a volcanic caldera. Plenty of giants and trolls, and thank goodness there's an otyugh in the midden. Hellhounds, of course.
Ashpeak is a training-grounds for fire giants (and now other giants). They have a magic rod that builds walls so the giants can practice knocking them down, and if that isn't a PF/3.x solution to a problem, then I don't know what is. The concept of having mock castles and keeps for the giants to train against is intriguing, but it doesn't seem to result in a really interesting scenario here. Plenty of traps, though.
The upper levels have the forge/smeltworks you'd expect in a fire giant lair, plus the inevitable salamanders (there you are, Perry!). Then there's the red dragon rookery...yikes. If you make it past here, you enter the levels containing the King and Queen, and it's still a rough go up here.
When you defeat the fire giants, you learn that the Storm Tyrant's flying castle is moored above the volcano. The adventure says you don't have any downtime between this adventure and the next, but you do have time to run back to the Cathedral to shrink some weapons if you're quick about it (?).
SHADOW OF THE STORM GIANT
Volstus the Storm Tyrant has a flying castle and an orb of red dragonkind. You can imagine where this is going. The PCs have to cross the top of the caldera and penetrate the force field around the castle, and the giants know they're coming. Just getting to the castle will require dealing with some ash giants, giant scorpions, and a giant who throws alchemical bombs.
Ironcloud Keep is big, and well-defended. In addition to giants, trolls, magical beasties, and the like, there are traps - some crazy ones. A 15th-level orc general. Weird stuff. Over fifty rooms of this. That's not a complaint, this is a huge dungeon. This will take a while. There are all sorts of evil ambassadors for variety. Oozes. More weird stuff. An old red dragon. And, finally, Volstus the Storm Tyrant. These last battles will go easier for you if you made friends with the dragon two adventures back.
Writing an homage to Against the Giants isn't easy. You have the giant ladder to play with, and certain things you have to throw in there, but you need to do it in a way that feels fresh. Both SKT and Giantslayer took a shot at it, with mixed results in both. That's the nature of it.
Luckily, we thieves and cannibals can steal from one to supplement the other, or weld them both into an unholy ettin of fun. There are encounters and lairs in Giantslayer worth stealing for your game, and perhaps less metaplot to excise while you're doing it relative to SKT. However, if you're adapting this for non-PF, you're going to miss out on some of the nice PF mechanical cleverness (much of which I'm sure I don't appreciate in reading through these).
If you're only going to pick up one of these to steal from, go with Forge of the Giant God or Ice Tomb of the Giant Queen. There's more stealable stuff per page in these two, and Forge in particular is low enough level that you're more likely to get a chance to run it.