Unique Tesla Coil Whoopee Cap
This item appeared in the backpack on 21st of October 2016, as Unique quality but clearly being an Unusual. It later became Unusual between 24th and 25th. The reason behind this glitch is unknown. It could have been just a bug within Backpack.tf.
Whoopee Cap
Team Fortress 2 Level 13 Hat
★ Unusual Effect: Tesla Coil
You'd have to be a jughead not to realize this cap is the pinnacle of fashion for the discerning youth.