The game seems to stop rendering new frames when holding down the grab button as a lizard. I've checked, and it only happens when I have this mod enabled.
Disabling all other workshop mods does not help with the issue. The game works normally once I stop attempting to bite. It doesn't matter whether or not something I can hurt is nearby.
It's not super consistent, but it seems to me like that's because it only happens after the bite is allowed to "wind up" fully - so biting as a pink or green lizard might not cause the freeze if you release the button before its mouth is completely open, but as a red lizard the freeze is instant because it bites instantly.
The following is the exception log from when I tested it without any workshop mods:

NullReferenceException: Object reference not set to an instance of an object
KillFeed.Mod.Lizard_Bite_HK (On.Lizard+orig_Bite orig, Lizard self, BodyChunk chunk) (at <e7078e0f57fa4b20b2e82e3a0b3ab0ba>:0)
DMD<>?815577216.Hook<Lizard::Bite>?1195599872 (Lizard , BodyChunk ) (at <c42227acf3d14fdf946e836e86f5a18b>:0)
Lizard.AttemptBite (Creature creature) (at <1014ff9a5d9941ab9e645d4f5c9384a5>:0)
LizardAI.Update () (at <1014ff9a5d9941ab9e645d4f5c9384a5>:0)
Lizard.Act () (at <1014ff9a5d9941ab9e645d4f5c9384a5>:0)
Lizard.Update (System.Boolean eu) (at <1014ff9a5d9941ab9e645d4f5c9384a5>:0)
Room.Update () (at <1014ff9a5d9941ab9e645d4f5c9384a5>:0)
RainWorldGame.Update () (at <1014ff9a5d9941ab9e645d4f5c9384a5>:0)
MainLoopProcess.RawUpdate (System.Single dt) (at <1014ff9a5d9941ab9e645d4f5c9384a5>:0)
RainWorldGame.RawUpdate (System.Single dt) (at <1014ff9a5d9941ab9e645d4f5c9384a5>:0)
ProcessManager.Update (System.Single deltaTime) (at <1014ff9a5d9941ab9e645d4f5c9384a5>:0)
RainWorld.Update () (at <1014ff9a5d9941ab9e645d4f5c9384a5>:0)

I have a hunch this might be related to the report of this mod causing crashes, although I'm not certain.