硬着头皮

硬 = 更 + 石 : Maud Younger (y) finds the snake which ate too much (更) in the engine's bathroom ((e)ng4), and it feels miserable. To make the snake feel better Maud massages the snake using two warm stones (石). As Maud massages the snakebshe finds that the snake's belly is really hard (硬).

着 = 目 + 羊 : In the aorta's kitchen (ao2), James II of England (zh) has first contact (着) with the sheep's (羊) wool. He is so amazed by the feeling that he can't stop cuddling with the sheep and finally falls asleep (着). Unfortunately the Eye of Providence (目) watches all of it and is so jealous that it catches fire (着).

着 = 目 + 羊 : James II of England (zh) cuddles with the sheep (羊) also on the roof of the aorta (e5), and again the Eye of Providence (目) catches fire (着) out of jealousy as it watches the action in progress(着).

头 = ⺀ + 大 : Tecumseh (t) is inspecting is depiction in the outhouse's kitchen (ou2). He's depicted as having a skull (mnemonic symbol for 头) head (头) with two petal leaves (⺀) in the eye holes, and having a robot (大) body.

皮 = ㇖ + 丿 + 丨 + 又 : Mnemonic symbol: a cow's hide.

皮 = ㇖ + 丿 + 丨 + 又 : Just inside the entrance of the space station Pocahontas destroys her cow's hide with a sickle because she decided to go vegan. Instead of leather she'll wear a banana peel as coat, boxing gloves as shoes and a big dinosaur bone as long hat.

皮 = ㇖ + 丿 + 丨 + 又 : New mnemonic symbol, since I also use the cow's hide for 革: leather shoes.