The crashes may be creepy but they are only errors, like most errors they can be different examples are: Resource packs not loaded, Game Crashed(or error code 1)... Some causes are: Lag(it's obvious), Outdated version(Obvious), Outdated client(maybe a crash) (it mean the server and the player have different version). Also an extremely rare cause that happened to me is that when i played java, bedrock non updated and it caused the crash.

But the crash you can make is here: Place TNT in a pyramid or import a world filled with TNT and ignite it to cause lag, another way is putting a repetition command block with the command /summon minecraft:wither (also say goodbye to your world!).