a large lump of rock that is heading for a planet
Halley's Comet is most probably a collection of ice, dust and rocks; a "dirty snowball" may be the most apt description. I'm not sure that "land" would fit the description.
No. That description most closely matches a comet.
Need a detalied description of all markings to answer.
That sounds like the description of a comet. However, please note that comets ONLY have a tail when they are close to the Sun. During most of their orbit, they are too far away from the Sun to have a tail.
a comet/meteorite
It is a comet.
Comets are named after the people who have discovered it or by the shape or after break away from a parent comet. eg: Halley's comet Tempel-Tuffle comet Biela's comet Encke's comet Ikeya Seki comet kooutek comet comet west comet Bowell comet IRAS -Araki-Alcock Comet Austin.
That sketchy description could be applied to a planet, a satellite, a moon, an asteroid, a comet, a meteoroid, or even an electron.
Halley's Comet
a dead comet is>......a out gassed comet.
The comet's tail is in front of the comet, not after
A comet head is the top of the comet like its nucleus is on the top of the comet.