Rolling Cactus

The Rolling Cactus is a placeable object that behaves similarly to the Boulder. A Rolling Cactus is stationary when placed. It begins to move (becoming a Rolling Cactus projectile) when hit by projectiles, Pickaxes, or Drills, or when the blocks under it are mined or Hammered. Its roll direction is determined by whether its horizontal position in the world is an odd or even number, regardless of the slope of the surface it is on (unless it is blocked on one side by blocks, in which case it rolls in the other direction).

When both blocks under a Rolling Cactus are removed or Hammered into a half-block, it will drop vertically until it hits a surface, then bounce and roll.

A Rolling Cactus projectile pierces unlimited entities. When a Rolling Cactus that has already started rolling falls onto a lower surface, it maintains its forward momentum while bouncing back up, releasing ~2-5 Rolling Cactus Spikes that travel in random directions. Hitting a vertical obstacle also releases Spikes, but destroys the Rolling Cactus. A Rolling Cactus' movement is not affected by liquids.

A stationary Rolling Cactus deals ~25 damage when a player touches it. A Rolling Cactus projectile deals ~70 / damage to players, ~70 damage to enemies and Critters, and ~60 damage to NPCs on contact. Each Rolling Cactus Spike deals ~20 damage, pierces entities, and breaks on contact with blocks.

Trivia

 * The tooltip is a reference to the opening lyrics of the song  by rapper, "They see me rollin', they hatin'..."