Cavern

Cavern the knife was the 29th tier of the Main Event in the 2019 Christmas Event. It is the only half of the Cavern Set that came from the event track, since its partner gun was unboxed from the 2019 Christmas Box. With the event over, the knife is only available through trading.

Why it is called Cavern

The blade is icy blue with black patches on it, meant to look like an ice cavern. The guard and handle are solid black, and the handle has tape wrapped around it. The look matches its gun partner, though the two are laid out differently: the gun fades from white to blue, while the knife keeps a flat icy blue base.

Cost

The curated row says each tier of that Main Event cost 600 Snow Tokens, according to the event page. The knife's own page says only that it was bought by purchasing the 29th tier, so the price per tier comes from the event page and not from the knife page.

Set

Cavern (Gun) is the partner, and the pair forms the Cavern Set. Collectors who want both pieces need to look in two places, because one was a tier reward and the other a box drop.