紅眼病

红 = 工 + 纟 : Mnemonic symbol: a little red book.

Helga Horse (hu) is reading the little red book (红) in the engine's kitchen ((e)ng2), when she discovers that it is being eaten by a silk worm (纟). She overreacts a little and wants to beat the silk worm with a steel beam (工).

眼 = 目 + 艮 : Inside of the anthill, Maud Younger played a prank on the Eye of Providence. She told it that she would apply a mask to alleviate the wrinkles around its eyes, but instead she just covered its whole eye with chewing gum.

病 = 丙 + 疒 : In engine's bathroom Brunhilde is proudly inspecting her bronze medal. She got it in a contest about having the craziest sickness by painting a colorful rash on her face.