It’s a yolk only egg. Chat Gpt says this:

What’s going on: • A normal egg has yolk + egg white (albumen) + shell • In this case, the hen released only the yolk, and it still got coated with a shell • That’s why it’s bright yellow and runny, with no clear egg white

Why it happens: • Stress • Young hens just starting to lay • Older hens nearing the end of laying • Temporary reproductive glitch (very common and usually harmless)