A window.

It takes a few tries and quite a bit of effort before you are satisfied with your transformation. By now you're sure you are indistinguishable from any other window in the tower. The shape, size, color, patterns, even the amount of dust and grime should be the same. The only way someone could spot you is if they've explored this tower multiple times before and no hero does that. Once a hero has done what they came to do, they leave for another place. Usually, a more dangerous place because heroes are crazy like that. You'd never do that, why would someone take that much of a risk? That's the sort of crazy thing continued resurrection does to a mind, apparently.

As you continue to contemplate the craziness of heroes and the reasons for it, you wait for someone weak enough to stumble into your room. This is not a problem for you, patience is a virtue to a trap monster like you after all. You can wait for as long as necessary. And you do, you wait for hours, for days, almost a week passes as you wait. And then you have to wait no more. You can hear people. Two of them. They are loud, which means they are either inexperienced and overconfident or very powerful. Considering the level of the monsters and treasures in this tower, the latter would be very unlikely.

When the two reach the door to your room, they become quiet for some reason. After an embarrassingly long time of fumbling with the barely-there lock, one of them comes into the room in a crouching position. You can't see the other hero, but the idiot that entered your room is definitely a thief in both interpretations. You assume what he's doing is meant to be seen as stealthily skulking around the room. To you, it looks more like a satirical caricature of it by a drunk bard.

When he 'skulks' by the window, you drop onto his neck and use entangle to wrap your tendrils around his limbs and start constricting yourself around his neck. You want to start gnawing on your victim or whip him with your tendrils, but you see that his health is already dropping fast. His struggle ends in mere seconds. That was surprisingly and disappointingly easy. If the other one is this weak you could just walk up and smack them with your tendrils. But it can't be that easy. Nothing could be this easy, right?