Jungle Creeper

Hardmode makes the Underground Jungle much worse to tunnel through, and this spider is a big part of why. It walks background walls the same way its cavern relative the Wall Creeper does, so a corridor with walls behind it hands the spider the ceiling and both sides at once. Strip those walls out and it drops to the floor and fights like any ordinary ground enemy.

Contact often leaves you with Acid Venom ticking away while you try to reposition. In Expert and Master it also picks up a ranged attack, spitting a wad of web that sticks you with Webbed and cuts your movement for a moment. That moment is usually enough for the rest of the jungle to reach you, which is the real danger rather than the spit itself. It needs a clear line to fire, so breaking sight stalls the attack, and every hit you land pushes the next shot back a little.

On For the Worthy and Zenith worlds those web shots leave real Cobweb behind where they land. Fight a group in a tight space and the room fills with blocks that bog you down and stay there after the spiders are dead.