I had a player in my server place an iron chest plate into the inventory of a tamed kangaroo and this instantly caused their client to crash. I tried to teleport to the location of the kangaroo and this caused my client to instantly crash as well.
I use optifine within my client but the player that found the issue does not have it installed.
The only solution was to kill the tamed kangaroo through commands, I have attached the crash report from my client below.

crash-2022-02-18_23.12.45-client.txt

Closing the issue due to it being fixed on a newer version, I didn't realise I was still on an old version. Sorry!