Crossbows
Sam used his energy vision to scan the surroundings a bit and after confirming that there is nothing else around except this snake, he sat down a bit and started examining it.
There are a few things, that he was surprised about.
The first one is that he wasn't able to sense the presence of this snake when it tried to attack him.
The second one is that this snake has more sanity than even some people on the first floor. It didn't just rashly attack without any consequences. It was sure that Sam would die after injecting that lethal dose of poison.
This is why, it caught him by surprise, before making that move.
Of course, then there is that tough leather skin that couldn't be pierced with normal spikes. And this time, even crushing didn't work, because this thing is pretty flexible. It managed to survive somehow.