Antlion Charger

Nothing summons it. It lives in the underground desert full time, and before Hardmode it also comes out onto surface deserts while a sandstorm is running. The real trigger is hardened sand walls, so anywhere those walls exist one can appear, which is why they sometimes turn up in pockets that do not look like desert at all. There are two sizes with a wide gap in what they hit for, so do not set your expectations from whichever one you met first.

The buried Antlion waits for you. This one comes to you, and it picks up speed the longer it has been running. Left alone with a straight line to work with it reaches a pace nothing on foot escapes, which looks like an oversight and has never been changed. It hops terrain as well, so the usual trick of putting a small ledge between you and a charging enemy does nothing. Knockback barely moves it either, so damage will not interrupt a run once it has started.

It is a big enemy in a biome made of small pockets. Most of the time you spot one, and the space it has to move in, well before it can reach you, which is enough to plan around or skip entirely. The gaps between chambers are narrow enough that your shots pass through while the body cannot follow, and a vertical shaft two tiles wide is the crudest version of that: it has nowhere to go and you keep firing.

This is where the Mandible Blade comes from, an autoswing sword well ahead of whatever else you own at that stage, and the trapping trick above is how new characters walk out of the desert holding one. The Banana Split comes off the same kills and covers your food buff for the trip.

In Expert and Master its damage drops once Plantera is dead rather than climbing, which is backwards from nearly everything else in the game. It stops being a threat at the exact point the rest of the world gets worse. By then the Basilisk is sharing the same tunnels and doing the same job much harder.