Constructs are the living creations of Mad Science. They fall into several general categories, usefully created, analyzed, and described by Karrion of the GG Yahoo Group:
Type I: Revives
Olga, sort of
Dead, brought back to life.
I guess we can't punish Victor for bringing Sparky back from the dead.
Examples: Tarvek Sturmvoraus; Agatha Heterodyne; The shell of Madame Olga may qualify; Zulenna Luzhakna may or may not have been successfully revived. Rudolf Selnikov's head has been revived, which seems to place him in this category, but perhaps his life support "jar" ✣ makes him a 'Borg - Type XI. If he ever gets that new body he wants ✣ , presumably he will become a Patch job - Type II.
Type II: Patch jobs
Baron Klaus
Dead, repaired with spare parts, brought back to life.
They'll fix you. They fix everything.
Examples: Baron Klaus Wulfenbach once the three Wulfenbach brothers were caught in a Laboratory accident the family downsized from there
Type III: Frankensteins
Built from parts of dead, brought to life.
LIFE! LIFE, DO YOU HEAR ME? GIVE MY CREATION... LIIIFE!
Examples: Punch and Judy - not confirmed in the comic, but in the novel though they are here termed Patchjobs.
Type IV: Freaks
Boris
Never dead, parts surgically added.
Smithers, fetch some surgical tools... and some ether...
Examples: Boris Dolokhov
Type V: Hydes
Altered by some process:
Here, drink this.
Examples: the Jägerkin
Type VI: Anthros
Krosp
Animal forms with human level (not that THAT means much) brain power.
...that is the Law. Are we not Men?
Examples: Krosp I
Type VII: Scratchbuilds
New, never-before-seen forms of life.
Examples: Zoing (possibly). most of the monsters of Sturmhalten's sewers
Type VIII: Sideshows
Not much different. Extra large or small; minor alterations such as added horns or abnormal color, i.e. unicorns or pink cats.
One of us! Gooble gobble, gooble gobble! One of us! One of us!
Examples: Mimmoths, Lapinemoths, the Monster Horse Beastie, Doctor Galliard Prunestoggle, Susa, Gritha Pantagruel
Type IX: Borgs
Wasp eater
Clank-construct combos.
We can rebuild him. We have the technology. We can make him better than he was. Better...stronger...faster.
Examples: Wasp eaters, Snapper Boikov, Radioheads, That guy behind Agatha ✣
Type X: Hybrids
Construct falling into more than one basic category, i.e. type IV/VI.
Oh my goodness! They've come back! As ninja pirate robot monkey clown bandito werewolf zombies!
Examples: Klaus may instead be a type II/III; the wasp weasels may be VIII/IX.
Type XI: WTF
Catchall for every thing that DOESN'T fit any category.
What the hell are you?
Examples: Not known, but Von Pinn, the Hoomhoffers, the Lackya, and the slaver wasps are not conclusively categorized.
Type XII: My mistake...
For the rare case of being commonly mistaken for constructs, but aren't. Aliens/extra-dimensional beings would qualify as well as when mother nature shows her sense of humor to fleeing townsfolk who have heard of, say, t-rex dinosaurs who were just brought in thru a time portal. Of course, some of these categories are subject to speculation and the conflicting classification systems of their creators. Keep an eye on Category:Constructs and the inhabitants thereof.