Slime Spear

A spear thrusts straight out and pulls back rather than sweeping, so it rewards holding a line instead of running past things. Against anything that closes on you head on it beats an early sword, and the reach lets you hit what is standing on the ledge above you without stepping into range.

The slime it smears on hit is brief and mostly incidental. Where the weapon genuinely matters is Skyblock, where the crafting station you start with makes this available before you have anything else worth swinging.