Tulog-mantika

No, it's generally a lighthearted or neutral description. However, if used to describe someone who missed a very important responsibility, the tone might be slightly critical.

Yes! It's very common to describe a pet dog or cat that won't wake up as 'tulog-mantika.'

The opposite is 'tulog-manok' (chicken sleep), which means a very light sleeper who wakes up at the slightest sound.

Probably not. It's quite informal. If you want to say you're a heavy sleeper in a professional context, say 'Mahimbing po ang tulog ko.'

Not necessarily. It only describes the depth of their sleep, not their work ethic. However, some people might jokingly link the two.

Because coconut oil solidifies and becomes unmoving when it's cold, just like a person in deep sleep.

You say 'Tulog-mantika ako.'

Usually, it's reserved for longer periods of sleep where one enters a deep state, but you can use it jokingly for a very deep 20-minute nap too.

Yes, 'mahimbing ang tulog' is the formal/standard equivalent.

Absolutely. It's a timeless idiom that hasn't lost its popularity.

Not directly. You would use 'naging' (became) or 'magiging' (will become) to show a change in state, e.g., 'Nagiging tulog-mantika ako pag pagod.'

Yes, because of Filipino mass media, almost everyone in the Philippines understands this idiom even if they speak other regional languages.