坏

坏 = 不 + 土 : In the airplane's bathroom, there is a clear sign that it is forbidden to enter the room with dirty feet. Helga Horse is quite spoiled though, so she enters right after she went to the muddy stables and spreads dirt all around.

不 = 丆 + 卜 : Bruno Bear (bu) is setting up a wind wheel (丆) with a voodoo staff (卜) in the space station's bathroom (Ø4). He also puts a "forbidden" sign (mnemonic symbol for 不) on it, to make clear that it may not (不) be stopped.

土 = 十 + 一 : Tommy Turtle (tu) wants to fix a cross (十) on a flute (一) in the space station's living room (Ø3). He uses dust and clay (土) to hold them together.