Venom
A sticky, tentacled creature that follows your cursor around the box. Its tentacles dynamically reach for the nearest available anchor points scattered across the surface — they let go and snap to closer ones when stretched past their reach. Quadratic Bezier with gravity-sag and lateral wobble for the rubbery feel; spring-damped motion + speed-driven squash-and-stretch for the body.
move your mouse around the box
The faint grey dots are the anchor points (~90 of them, scattered at mount and re-scattered on resize). Each frame, every tentacle slot re-picks its nearest unused anchor within reach via a greedy nearest-neighbor scan. A quadtree would scale this to thousands of anchors; at this count the linear pass is fine.
The tentacle tipdoesn't teleport to the new anchor — it lerps toward it, so re-attachment reads as an elastic whip rather than a cut.