The Hvy Dozer (Bulldozer) is a continuous tracked tractor equipped with a substantial metal plate used to push stuff
You can also find a Bulldozer at the southeast edge of the Los Santos International Airport (Both in Story Mode and in GTA Online).
This one is more challenging to steal, as breaking into the airport will give you a Three Stars Wanted Level
Bulldozer lifting a Police Cruiser:
Bulldozer lifting a Los Santos Transit Bus:
Bulldozer lifting a FlyUS Jet: