HyperCard was an application that used to come free with each Macintosh computer.
It's basically cell animation - I simply drew a slightly different image on each subsequent card and then ran them in a sequence. Similar to the technique used in animated movies until computer animation took over. I use computer animation via Adobe Premier now.
I used to feel bad that this HyperCard sequence made Erwin Schrödinger look like a guy who was mean to cats, but then I found out Schrödinger sexually abused teenaged girls so now I'm glad he looks like a jerk.