Pythons are snakes. They are rarely remarkable or dangerous as they are very slow-moving and do not do a particularly large amount of damage, although they can use all three of their attacks in one turn, and their grabbing attack can trap the player.
Pythons are often a source of YASD when players forget that they have a drowning attack. Unlike giant eels and other sea monsters with drowning attacks, they are not found near water any more frequently than other monsters, so it is easy to forget that they are capable. It doesn't help that the message (“The python grabs you!”) is different than the “swings itself around you” used for all of the other monsters capable of drowning players. On servers and variants that support it, setting a MSGTYPE rule for this message can help to remind you that drowning is possible.
Greased armor can also protect from the crushing/drowning attack.
- See the encyclopedia entry for snake.