Hollow Knight: Invulnerability [1.1.1.8] file

This mod will prevent all types of damage, including environmental hazards. It also negates knockback effects. This means you can walk right through spikes, enemies, etc. (Nail-jumping still works though!) Unfortunately, this also means that you may occasionally fall through things you aren't supposed to fall through and get stuck. If this happens, don't panic, the game is not broken. Simply reload (by quitting to menu) and you will respawn at the last bench, as usual.

Invulnerability doesn't affect your save file, so you can turn it on and off at will without any long-term effects. Instructions for enabling and disabling the mod are in the readme.