Jungle town, you know how this goes. Hidden Aztec civilizations, dinosaurs, diamonds, cannibals sacrificing virgins to volcanoes - more adventure than horror. Movement with vehicles is halved.
All your stuff is likely to rot. Roll a d10 each day; on a 1, something's started to rot, and will be shittier. (If you're using the Anti-Hammerspace rules, roll a d6 - everything in that container is starting to go). Food won't keep long.
3-4: Woolly Mammoth
5-6: Giant Snake with rubies for eyes
7-8: King Kong.
9-10: 2d4 Amazon women riding giant pumas. Will abduct strong party members to mate with.
11-12: 2D4 cannibal Aztecs with poison blowpipes.Will capture PC's for sacrifice.
13-14: Triceratops! Ancient, armoured, and corrupted by time.
15-16: 2D6 horrible monkeys. Act cute, then steal parties belongings and flee.
17-18: 2D4 Tiget pack. Lead by giant, noble pack leader.
19-20: 2d6 Pterodactyls! Seize PC's and take them to nest.
21-22: Small stone remnants of ruined Aztec temple around. Ruined stone heads will spit poison darts, stone floors in undergrowth will send poisoned stakes stabbing up.
23-24: Giant stone monkey head with valuable idols around. Monkey shoots laser eyes at disrespectful trespassers. Secret knobs on the monkey's ears open the mouth, leading down to a series of catacombs.
25-26: Tarantula in someone's sleeping bag.
27-28: A river cuts through the path. It's full of piranhas.
29-30: Plants grow over and consume party while they sleep.
31-32: Poison snakes in the undergrowth. Then more snakes drop from above. The hollow trees surrounding the party burst open, full of snakes. The party takes to their weapons, only to realise that they have been wielding camouflaged snakes this entire time. They try to yell, but can only hiss.
33-34: Dark cave holds tribe of sleeping vampire bats. Making too much noise around it will awake them.
35-36: Vines are the tongues of giant, tree-dwelling toads.
39-40: Massive venus fly trap - pitcher plant.
41-42: A hoard of smuggled diamonds!
43-44: Talking parrots, will recite directions to lost treasure
45-46: Jungle-mad explorers from colonizing civilization live in remains of fort.
47-48: Tameable, ridable pterodactyl
49-50: Lake, hidden ruined temple at bottom
51-52: Native village. Cannibals. Likely to turn hostile, but will be friendly if party proves themselves.
53-54: A river. A native fisherman floats down it on canoe, greets party in native tongue.
55-56: Mayan altar, overgrown - skeleton clutching jewels underneath.
57-58: Ramshackle outpost of civilization. Greet PC's eagerly, ask for news from outside world. Mistreat native slaves.
59-60: Massive fruit of many colours. Edible, delicious, causes euphoria.
Colour and Terrain
61-62: Thick bush covers path, must be hacked aside. Hard to see far.
63-64: Heavy rain starts. It won't stop raining for months.
65-66: A river cuts through the path.
67-68: Gorilla nest.
69-70: Party comes to top of cliff- must find a way down.
71-72: Sloths in the trees.
73-74: Clearing with lake. Elephants drink from it.
75-76: Really heavy rain. Impossible to see two feet ahead.
77-78: Path stops. No way to know where to go. Party is likely to get lost.
79-80: A river, going the same direction as the party.
81-82: 2d10 Aztec ghosts haunt the ruins of their civilization. Some will be priests, some warriors, one high priest.
83-84: d4 Blood-crazed kali worshippers, whipping 2d10 child slaves. Working some kind of mine-cart system for unknown ends.
85-86: Glimmering Jim. A portal that looks onto blue sky, in the shape of a man's silhouette. It's on a hill with charms, picket fence surrounding it. Party feels hungry when near it. Anything put through it will not be seen again. Anyone in the nearby area when a sentient being is put through it will experience total wild ecstasy, lose control, and go on a bender for 1d4 hours.
87-88: Rake-Face Jake. Massive boar, six human hands, antlers. Terrorizes nearby native village.
89-90: Deep chasm in jungle. Looks almost like an impact crater. Charms and signs from many different cultures surround it. "She came from the sky and became the Mother." "The Mother has been waiting." "The Mother has been dreaming of the day she returns."
91-92: Active Volcano. Party sees lava flowing nearby, possibly causing forest fire. Chanting echoes from it. A temple is suspended over the mouth of the volcano by breakable stone and vines.
93-94: Miles and miles of land covered waist-deep in tiny animal bones.
97-98: Party member trips on something in undergrowth. The leaf litter conceals a massive centuries old ziggaraut under the jungle. Birthplace of civilization: Mayan, Sumerian, Egyptian and Chinese ruins below.
99-100: El Dorado! Totally paved in gold and precious jewels. It will, of course, be the parties downfall in one way or another.