Denis Leary ROASTS Dick Clark -- 'Leather-faced Syrup-Voiced Lizard Person'

Dick Clark's only been dead a few hours ... but the roasting has already begun ... this time, it's Denis Leary leading the charge.

Leary went to his Twitter a few minutes ago and wrote, "With Dick Clark dead, Casey Kasem now reveling in his status as last and reigning king of leather faced syrup voiced lizard people."

There's more -- Denis wrote, "I'm gonna package a Dick Clark Hologram mc'ing a Tupac Hologram summer tour."

So, we gotta as ask ...