You only make one trip to the Himalayas, but you must first get the digital camera at Loch Ness (letting air out of the driver's tires).
At the mountain, climb up and left to locate the Sherpa guide. He will climb the ropes with you. As you reach each "ring" in the mountain trail, click it to tie off the rope, then wait until the guide catches up. Zig-zag up the trail to reach the monastery.
The head monk will not release the Yeti scalp, but does give you a lantern to help on your quest. Climb above the roof and play a game against a monk guarding the trail. When you win, go farther up and left to find a footprint in the snow near some flowers. Take a photo that you can show to Mews. Climb back down (a shorter trip) using the rope bridge down the right side.
In the monastery.
On Cryptids, you go to the Himalayas and ask for the Yeti skull. He will not give you it, but you will be handed a lantern to 'light your way' as he claims.
Climb up to the first snow-covered level, and go left, and he will meet you.
At the monastery in the Himalayas. You also need the matches from the pub at Loch Ness.
Climb up and go left. He is just down the trail at upper left.
You have to look for Bigfoot/Yeti in the Himalayas, the Jersey Devil in New Jersey, the Loch Ness Monster in the Loch Ness in Scotland and the Chupacabra in Puerto Rico.
You need the lantern from the Himalayas, and the matches from Loch Ness, so that you can travel in the dark forest at New Jersey.
There are matches in the Pub at Loch Ness. Go right from the loch and they are on the bar in the Pub. You will need them for the lantern you get in the Himalayas.
Go back to the Himalayas, and now you can climb a rope at the right side (above the helicopter), and go back to the monastery for the lantern.
He is not on Cryptids Island. He is on Counterfeit Island.
There are matches on the bar in the pub at Loch Ness. You need them to light the lantern from the Himalayas when you are on the motorcycle in New Jersey.
The monastery is at the top of the mountain at the Himalayas. You can see the head monk there, and you can climb the trail above the monastery to seek clues.