how does it look like?
Chicken-sized, small, bipedal, long hind legs; the forelimbs were smaller than the hindlimbs; the hand bore two large, clawed digits and a third, smaller digit that may have been non-functional; delicate long narrow skull with tapered snouts.
Compsognathus
For decades, "Compsognathus" were famed as the smallest dinosaurs known; the first specimen collected was around in length. However, dinosaurs discovered later, such as "Caenagnathasia", "Microraptor" and "Parvicursor", were even smaller. The largest "Compsognathus" specimen is estimated to have weighed somewhere between .

"Compsognathus" were small, bipedal animals with long hind legs and longer tails, which they used for balance during locomotion. The forelimbs were smaller than the hindlimbs. The hand bore two large, clawed digits and a third, smaller digit that may have been non-functional. Their delicate skulls were narrow and long, with tapered snouts. The skull had five pairs of fenestrae (skull openings), the largest of which was for the orbit (eye socket), with the eyes being larger in proportion to the rest of the skull.
what is compsognathus? A genus of small, bipedal, carnivorous theropod dinosaur.
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Compsognathus [SEP] Description
For decades, "Compsognathus" were famed as the smallest dinosaurs known; the first specimen collected was around in length. However, dinosaurs discovered later, such as "Caenagnathasia", "Microraptor" and "Parvicursor", were even smaller. The largest "Compsognathus" specimen is estimated to have weighed somewhere between . "Compsognathus" were small, bipedal animals with long hind legs and longer tails, which they used for balance during locomotion. The forelimbs were smaller than the hindlimbs. The hand bore two large, clawed digits and a third, smaller digit that may have been non-functional. Their delicate skulls were narrow and long, with tapered snouts. The skull had five pairs of fenestrae (skull openings), the largest of which was for the orbit (eye socket), with the eyes being larger in proportion to the rest of the skull.