Note: This page is taken from n.wikia.com.
(As written in the N in-game help)
According to legend, in pre-robotic times there existed a race of large, spikey stone bastards, whose complete invulnerability and hereditary hatred of heroic Italian plumbers led to their persecution, and eventually to extinction
Thankfully they've been recreated, in robot form, and 3 of their 4 sides have been rendered harmless.
A thwump is basically a square block with one blue deadly electrified side and three non-electric sides. A thwump's line of sight is rather narrow, and extends to the adjacent row or column. This means one can draw thwumps down without ever being in any danger if standing in the right place. Downward and upward-facing thwumps can only see the ninja in the column the deadly side is in, and the adjacent columns to it. Left and right-facing thwumps can only see the ninja in the row the deadly side is in, and the adjacent rows. However, thwumps can't see behind themselves, so it's safe if the ninja is back there. Here's a picture to clarify things:
The [approximate] area that the thwumps can see is shown in yellow. The ninja is safe because the thwumps cannot see him. If the ninja was to move into one of the yellow areas, the thwump would rush forward in the direction of the arrow in an attempt to electrocute the ninja or, at least, crush him. Upon contact with a tile, the thwump will then slowly return back to its original position.
Thwumps only have one deadly side. The ninja can walljump off of thwumps, and in some cases even ride them. Also, they do not collide with objects other than locked doors and trap doors, so the player cannot hide behind those, unfortunately. Additionally, one has to watch out for thwumps positioned with a wall at their back. If the player rides them, it's possible to get crushed against the wall. However, if the player is not dead center against said wall and is positioned correctly, it is possible for them to instead be squeezed by the thwump and be blasted off at great speed. This trick is very frequently employed in 1.4 in 83-3: Bricklayer (by xRyuenjinZeroEX) by highscorers.
- ↑ A reference to Super Mario Bros.