An animated Neon Sign. Has animation, normal mapping, simplified constant night mode. Why constant nightmode? Check its daymode, compare it to other daymodes in TS12 and you will see the difference.
Place this neon sign and the similar but with reverse arrow neon sign back to back, mount them 90 degrees from a suitable wall, instant 2 sided neon sign.
Can be converted to TS09 and TS10 (and will work there) by changing the version number in the config.txt from version 2.9 onwards.