Citation: Daniel Konstanski, The Secret Life of LEGO Bricks: The Inside Story of a Design Icon (Unbound, 2022). — p. 266.

Setting out to create collectible ninja dragons, the development team wanted to avoid using constraction-style ball-and-socket joints, which didn’t look organic enough. Instead, the developers envisioned a new class of components: mini-ball joints. Each would work in the same way as their larger cousins, but, at a fraction of the size, they would not stand out so much in a model and be easier to conceal, while still imbuing excellent functionality.

Prototypes of mini-ball joints were made for inclusion in the collectible dragons envisioned for the first wave of LEGO NINJAGO. However, they turned out to be far trickier to get right than expected. Obtaining enough friction so that limbs wouldn’t droop, but not so much that they were hard to move, proved challenging on the drastically reduced surface area available. It quickly became clear that there was no way they could be perfected in time. Mini-ball joints were not abandoned, however, and all the kinks were eventually ironed out. Several designers who worked on LEGO NINJAGO went on to join the team for LEGO Legends of Chima and they resurrected them for a similar use. Mini-ball joints debuted in LEGO Chima in rideable creatures called Legend Beasts, with essentially the exact purpose for which they were originally envisioned. Those elements have gone on to be used extensively in numerous themes.

The smaller Towball joint was developed for the initial Ninjago release to create small brick-built dragons, but the parts took too long to get right, and debuted a few years later in LEGO Chima sets.