Head Shake

The element jitters quickly back and forth along one axis.

Add a "Shake" effect (also called an error shake or invalid input shake) to [where].
The element should jitter quickly left and right a few times and stop exactly where it started: fast and firm.
Play it once each time the error happens rather than looping, and pair it with a visible error message so the meaning does not rely on motion alone.

The element rocks side to side with tilt like a wobbly object.

Add a "Wobble" attention effect to [where].
The element should rock side to side with a tilt, starting with a big sway that shrinks with each swing until it settles.
Play it once when triggered, and keep neighbouring content from shifting.

The element swings back and forth from its top edge like a pendulum with decaying amplitude.

Add a "Swing" attention effect to [where].
The element should swing back and forth like a hanging sign, starting with a wide swing that quickly dies down.
Pivot it from its top edge rather than its center, and play it once when triggered.

The element skews back and forth with decaying amplitude like a wobbling jelly.

Add a "Jello" attention effect (also called jelly) to [where].
The element should skew back and forth like a wobbling jelly, strong at first and quickly settling to rest.
Play it once when triggered, and keep the element's footprint so nearby content does not shift.

The element scales in a double-beat rhythm like a beating heart.

Add a "Heartbeat" effect (also called heart beat) to [where].
The element should swell and relax in a quick double beat, then rest briefly before the next beat, like a beating heart.
Loop it seamlessly with the rest kept between beats, and stop it for users who prefer reduced motion.

A copy of the element scales up and fades out repeatedly like a radar ripple.

Add a "Ping" effect (also called a radar ping or pulse ring) to [where].
A copy of the element should grow outward and fade away, again and again at a steady pace, while the element itself stays still.
Draw the ring as a separate layer so it never changes the layout, and stop the loop for users who prefer reduced motion.