Goblin AC13+ HD1-1 Move20 Damage 1d6 Weapon and Ranged.
Unless stated otherwise the monster has a chance to hit of 1/2 HD. That is also it's Difficulty + 10 for any saves from it's abilities unless otherwise stated. The 1/2 HD is also the number rolled for any saves or actions done unless otherwise noted.
A Goblin Bloodcaster AC 11 HD3-3 Move20 Damage Staff 1d6.
Has the spells of Magic Missile x3 and Sleep DC 12 to Save.
Nothing more to it than that. But just say you want to create a more "modern" monster. No problem!
Garron Beast AC16 HD7 Move60/30c Bite 1d8, Claws 1d6 x2, Tail 1d6
The Garron Beast is a creature that is know to attack entire parties, They are very intelligent beast and collect treasure for various missions of evil. They can track +3. The Garron Beats appears to look like a cross between a tiger and a lizard. It's origins are unknown but many scholars think Garron Beast are demonic.
Well there seems to be very little difference in function just in how much of the page it takes up.