I found in an old box these animal characters.
They are all LEGO original (the logo is present on all their parts).
They are 25, maybe 30, years old. I think is the Fabuland series. I wonder if there is any way to discover how many they were and if there is any way to complete the collection.
If you were to collect one of every animal type (excluding colour variations) you would at the very least need 20 Fabuland Figures:
There are variations between figures in the copyright markings on the back of the legs, face printing between similar figures. In addition to the standard figures there are 72 variations of Fabuland Keychains.
I'm not sure how official of a list you are looking for, but there are 93 Fabuland minifigs listed on Bricklink:
Here's the full list from there:
fab1a Fabuland Figure Bear 1
fab1c Fabuland Figure Bear 2
fab1b Fabuland Figure Bear 3
Fab2k Fabuland Figure Bulldog 1
fab2e (Inv) Fabuland Figure Bulldog 1 with Fire Helmet
fab2a (Inv) Fabuland Figure Bulldog 1 with Police Hat
fab2b Fabuland Figure Bulldog 2 with Police Hat
fab2d Fabuland Figure Bulldog 3
fab2c (Inv) Fabuland Figure Bulldog 3 with Police Hat
fab2j Fabuland Figure Bulldog 3 with Police Hat and Post Pattern
fab2l Fabuland Figure Bulldog 6
fab2g (Inv) Fabuland Figure Bulldog 6 with Fire Helmet
fab2f Fabuland Figure Bulldog 7 with Fire Helmet
fab2h Fabuland Figure Bulldog 8 with Fire Helmet
fab2i Fabuland Figure Bulldog 9 with Fire Helmet
fab3a Fabuland Figure Bunny 1
fab3b Fabuland Figure Bunny 2
fab3c Fabuland Figure Bunny 3
fab3d Fabuland Figure Bunny 4 - Collar Pattern
Fab3e Fabuland Figure Cat 1
fab3f Fabuland Figure Cat 2
fab3g Fabuland Figure Cat 3
fab3h Fabuland Figure Cat 4
fab3i Fabuland Figure Cat 5
fab4a Fabuland Figure Cow
fab4b Fabuland Figure Crocodile 1
fab4c Fabuland Figure Crocodile 2
fab4d Fabuland Figure Crow 1 with Aviator Helmet and Black Eyes
fab4h Fabuland Figure Crow 1 with Aviator Helmet and White Eyes
fab4e Fabuland Figure Crow 2
Fab4f Fabuland Figure Crow 3 with Aviator Helmet
Fab4g Fabuland Figure Dog
fab5a Fabuland Figure Elephant 1
fab5b Fabuland Figure Elephant 2
fab5c Fabuland Figure Elephant 3
fab5d Fabuland Figure Elephant 4 with Yellow Hat and Black Eyes
fab5i Fabuland Figure Elephant 4 with Yellow Hat and White Eyes
fab5e Fabuland Figure Fox 1
fab5f Fabuland Figure Fox 2 with Yellow Hat
fab5g Fabuland Figure Goat 1
fab5h Fabuland Figure Goat 2
fab6e Fabuland Figure Hippo 1
fab6f Fabuland Figure Hippo 2 - Necklace Pattern
fab001BHP Fabuland Figure Hippo 3 - LEGO Centre / Birkenhead Point Sydney Pattern
fab6a Fabuland Figure Horse 1
fab6b Fabuland Figure Horse 2
fab6c Fabuland Figure Horse 3
fab6d Fabuland Figure Horse 4
fab002BHP Fabuland Figure Horse 5 - LEGO Centre / Birkenhead Point Sydney Pattern
fab7a Fabuland Figure Lamb 1
fab7b Fabuland Figure Lamb 2
Fab7h Fabuland Figure Lamb 3
fab7d Fabuland Figure Lamb 4
fab7e Fabuland Figure Lion 1
fab7f Fabuland Figure Lion 2
fab7g Fabuland Figure Lion 2 with White Hat
fab8a Fabuland Figure Monkey 1 with Light Gray Hat
fab8b Fabuland Figure Monkey 1 with Red Hat
fab8f Fabuland Figure Monkey 2
fab8h Fabuland Figure Monkey 3 with White Hat
fab8d Fabuland Figure Monkey 4
fab8e Fabuland Figure Monkey 5
fab8i Fabuland Figure Monkey 6 with White Hat
fab8c Fabuland Figure Monkey 7
fab8g Fabuland Figure Monkey 8
fab9a Fabuland Figure Mouse 1
fab9b Fabuland Figure Mouse 2
fab9d Fabuland Figure Mouse 3
fab9c Fabuland Figure Mouse 4
fab9e Fabuland Figure Mouse 4 with White Cap
fab9f Fabuland Figure Mouse 6
fab9g Fabuland Figure Mouse 7
fab10a Fabuland Figure Panda 1
fab10b Fabuland Figure Panda 2
fab10c Fabuland Figure Parrot
fab11a Fabuland Figure Pig 1
fab11b Fabuland Figure Pig 2
fab11c Fabuland Figure Pig 3
fab11d Fabuland Figure Pig 4
fab11e Fabuland Figure Pig 5
fab11f Fabuland Figure Pig 6
fab11g Fabuland Figure Pig 7
fab7c Fabuland Figure Poodle
fab14a Fabuland Figure Poodle with Black Eyes
fab14b Fabuland Figure Poodle with White Eyes
fab12a Fabuland Figure Raccoon 1
fab12b Fabuland Figure Raccoon 2
fab12d Fabuland Figure Raccoon 3
fab12h Fabuland Figure Raccoon 4
fab12c Fabuland Figure Raccoon 5
fab12f Fabuland Figure Walrus 1
fab12e Fabuland Figure Walrus 2
fab12g Fabuland Figure Walrus 3 - Anchor Pattern
You can purchase these on Bricklink as well in order to complete your collection.
The Fabuland figures and sets were produced between 1979 and 1989. According to the BrickLink Catalog - which has the most comprehensive list of LEGO minifigures ever released - there are 93 Fabuland characters. Some of these however are slight variations (i.e. same animal, different color torso/legs/arms). You can find the full list here: List of LEGO Fabuland Figures
While some of the Fabuland characters can still be found fairly easily, others are very rare. Also, as the figures are so old, it can be difficult to find them in good condition. As demonstrated by the crow in the last row of your picture, the facial printing didn't stand up well to regular play. The hip and arm joints can also get very loose if the figures were played with regularly.
