Tool's Maynard James Keenan battled COVID-19 twice.

The 56-year-old rocker has revealed he had the "ugly" respiratory illness for a second time in November and was hospitalised on December 1, after it "kind of" progressed into pneumonia.

Sharing his symptoms, he told 'STROMBO' on Apple Music Hits: "Ugly, ugly. Couldn't breathe. I could barely put two words together without going into a coughing fit that, you know? It ended up kind of also progressing into pneumonia. So, if I stayed in the hospital, they said, 'Okay, we can keep you here, but you're fighting 12 other people for a bed and a ventilator we don't have, so what do you want to do?' I'm like, 'Well, I need to breathe and I need to sleep.' So, you're just treating symptoms at that point. There's nothing you can do other than treat the symptom, so for a real cough medicine, not the c*** over-the-counter and then like an inhaler, and some antibiotics to fight the pneumonia and strap the f*** in."

The 'Third Eye' star first had coronavirus in October.

He said at the time: "I'm still dealing with the residual effects. But it was ugly. I survived it, but it wasn't pretty. So I definitely had to deal with that.”

Maynard previously implored everyone to take the pandemic “seriously" and wear face masks and social distance in order to help flatten the spread of the virus.

He said: "I knew what I went through and I know what I'm still going through, so I would recommend that you take this seriously, but I feel like that's just going to fall on deaf ears. It's just going to be a polarised, politicised statement, so it's pointless. In that case, I'm just going to worry about keeping my family safe and keeping my friends safe."