Adding Any Mod Causes Spawn Eggs to Revert to Old Textures or Disappear

I've encountered an issue in Minecraft where some hidden spawn eggs appear completely invisible, with their textures missing entirely.

‌Steps to Reproduce:‌

Launch the game and load an existing world save.

Switch to Creative Mode.

Navigate to the spawn egg list in the creative inventory.

‌Expected Result:‌

All spawn eggs should display their correct, up-to-date textures without any missing or misplaced visuals.

‌Actual Result:‌

Certain hidden spawn eggs either revert to outdated legacy textures or show no texture at all, appearing as invisible items in the inventory.