Stagnant Creek
The Watcher in the Water#69 (x3/x1)
Location
3 (3)
Swamp.  

When Revealed: Discard the top card of the encounter deck. If the discarded card is a Tentacle enemy, add that card to the staging area and raise each player's threat by 5.

When they came to the northernmost corner of the lake they found a narrow creek that barreed their way. It was green and stagnant, thrust out like a slimy arm towards the enclosing hills.
–The Fellowship of the Ring