In Dungeon Keeper, the Query tool is for use on creatures. Hovering help-text will appear over most features without the use of this tool. Once a creature is Queried, the screen stays locked onto it as it moves about. Information on the individual is displayed across separate panels that can be cycled through. Dungeon Keeper's in-game help and Manual are known to have a lot of inaccurate descriptions for items displayed by this tool; see notes on certain entries below.
More information can be found on the Category:Creatures page. 
"How angry the creature is."
A sliding scale of the creature's Anger level.
Experience and LevelEdit
"The creature's experience level."
Imposed over a bar indicating the creature's progress towards achieving the next level-up. Every level over 1 will increase most of creature's other stats by 35%. This includes spell strength and the ability to perform jobs such as researching or manufacturing.
Name and HealthEdit
The name is imposed over the health bar. The numeric health total isn't displayed with Query.
Weapon swings and spells currently known to the creature are displayed in the first tabs. There can be up to ten of them. The numbers correspond with the keys for readying the skill while Possessing the creature. At the very least, there will be some kind of basic Creature Spell in slot #1, usually the Hand to Hand swing, ready for use.
"The number of enemies the creature has slain."
"The amount of gold the creature is carrying."
Payday wages do not add to this figure. This gold gets ejected if the creature is killed.
"The chance a creature will avoid a blow."
This is actually an armor-thickness rating that will reduce all incoming damage as a fraction of 255. Note that "Defence" is capped at 204(~80% damage reduction).
Age/Time in DungeonEdit
"The length of time you have employed the creature."
"The chance that a creature will do a double attack or a double defence in combat."
Specifically this number is the probability, as a fraction of 255, that a creature will do a double attack/cast or make two defensive Skill rolls (see below). Melee attacks and defensive rolls are still not guaranteed to work.
"The amount of damage the creature inflicts upon its enemies."
This is understood to be the exact health damage inflicted per swing. It is mitigated by the damage reduction score, Defence (above), and possibly negated by the defensive roll.
"The creature's salary in gold."
"The creature's ability to perform tasks."
This value has nothing to do with tasks. Research, Manufacturing, Scavenging, and Training Skill have their own respective values. In melee, a defender makes a Skill roll opposing the swinger's Dexterity; if the roll succeeds, the attack is dodged.
"The chance a creature will avoid a trap or an enemy weapon."
Traps cannot be dodged. This attribute appears to determine the creature's chance of striking a target in melee combat, not avoiding a swing, and it opposes the target's Skill.
"As if you care. Blood is blood, right?"
Supposedly just an aesthetic feature. From the Manual: "You, as Dungeon Keeper, must know your creatures if you are to command them effectively. Being aware of a creature’s blood type gives you greater power of them. Apart from this, it does nothing."