There are a lot of animals, in case you are wondering, but they seem to thin out the deeper you go:
Code:
MariaDB [codexangband]> select name,glyph,rarity,depth from angband_420_monster where flags like "%ANIMAL%" order by cast(depth as signed);
+-----------------------------------+-------+--------+-------+
| name | glyph | rarity | depth |
+-----------------------------------+-------+--------+-------+
| scrawny cat | f | 3 | 0 |
| scruffy little dog | C | 3 | 0 |
| wild dog | C | 1 | 1 |
| fruit bat | b | 1 | 1 |
| rock lizard | R | 1 | 1 |
| soldier ant | a | 1 | 1 |
| white worm mass | w | 1 | 1 |
| giant white mouse | r | 1 | 1 |
| large white snake | J | 1 | 1 |
| giant white centipede | c | 1 | 1 |
| giant yellow centipede | c | 1 | 1 |
| crow | B | 2 | 2 |
| wild cat | f | 2 | 2 |
| blue yeek | y | 1 | 2 |
| salamander | R | 1 | 2 |
| cave spider | S | 1 | 2 |
| white harpy | H | 1 | 2 |
| giant black ant | a | 1 | 2 |
| green worm mass | w | 1 | 2 |
| giant green frog | R | 1 | 2 |
| metallic green centipede | c | 1 | 2 |
| Fang, Farmer Maggot's Dog | C | 1 | 2 |
| Grip, Farmer Maggot's Dog | C | 1 | 2 |
| clear worm mass | w | 2 | 3 |
| giant white ant | a | 1 | 3 |
| yellow worm mass | w | 2 | 3 |
| giant white louse | I | 1 | 3 |
| metallic red centipede | c | 1 | 3 |
| metallic blue centipede | c | 1 | 3 |
| cave lizard | R | 1 | 4 |
| silver mouse | r | 1 | 4 |
| blue worm mass | w | 1 | 4 |
| giant white rat | r | 1 | 4 |
| large grey snake | J | 1 | 4 |
| red worm mass | w | 1 | 5 |
| copperhead snake | J | 1 | 5 |
| giant green dragon fly | F | 2 | 5 |
| giant white dragon fly | F | 2 | 5 |
| rattlesnake | J | 1 | 6 |
| giant brown bat | b | 1 | 6 |
| giant gold dragon fly | F | 2 | 6 |
| giant black dragon fly | F | 2 | 6 |
| wood spider | S | 3 | 7 |
| night lizard | R | 2 | 7 |
| giant red frog | R | 1 | 7 |
| crow of Durthang | B | 3 | 7 |
| terrified yeek | y | 1 | 8 |
| giant salamander | R | 1 | 8 |
| yeti | Y | 3 | 9 |
| cave bear | q | 1 | 9 |
| king cobra | J | 2 | 9 |
| black harpy | H | 1 | 9 |
| giant red ant | a | 2 | 9 |
| giant grey rat | r | 1 | 9 |
| giant black louse | I | 1 | 9 |
| wolf | C | 1 | 10 |
| panther | f | 2 | 10 |
| giant spider | S | 2 | 10 |
| giant fruit fly | I | 3 | 10 |
| giant white tick | S | 2 | 10 |
| Orfax, Son of Boldor | y | 3 | 10 |
| hippogriff | H | 1 | 11 |
| tiger | f | 2 | 12 |
| white wolf | C | 1 | 12 |
| black mamba | J | 3 | 12 |
| master yeek | y | 2 | 12 |
| stegocentipede | c | 2 | 12 |
| nether worm mass | w | 3 | 12 |
| killer brown beetle | K | 1 | 13 |
| Boldor, King of the Yeeks | y | 3 | 13 |
| warg | C | 2 | 14 |
| giant flea | I | 3 | 14 |
| griffon | H | 1 | 15 |
| wererat | r | 2 | 15 |
| dark hound | Z | 3 | 15 |
| clear hound | Z | 3 | 15 |
| light hound | Z | 3 | 15 |
| giant tan bat | b | 2 | 15 |
| giant tarantula | S | 3 | 15 |
| giant clear centipede | c | 2 | 15 |
| craban | B | 4 | 16 |
| umber hulk | X | 1 | 16 |
| grizzly bear | q | 2 | 16 |
| 2-headed hydra | M | 2 | 17 |
| giant red scorpion | S | 1 | 17 |
| blink dog | C | 2 | 18 |
| cold hound | Z | 3 | 18 |
| fire hound | Z | 3 | 18 |
| hummerhorn | I | 4 | 18 |
| energy hound | Z | 3 | 18 |
| werewolf | C | 1 | 20 |
| air hound | Z | 3 | 20 |
| sasquatch | Y | 3 | 20 |
| earth hound | Z | 3 | 20 |
| water hound | Z | 3 | 20 |
| blood falcon | B | 2 | 20 |
| 3-headed hydra | M | 2 | 20 |
| Mirkwood spider | S | 2 | 20 |
| sabre-tooth tiger | f | 2 | 20 |
| blue dragon bat | b | 1 | 21 |
| wyvern | d | 2 | 22 |
| neekerbreeker | I | 4 | 22 |
| killer stag beetle | K | 1 | 22 |
| giant yellow scorpion | S | 1 | 22 |
| phase spider | S | 2 | 23 |
| red dragon bat | b | 1 | 23 |
| giant silver ant | a | 1 | 23 |
| werebear | q | 2 | 24 |
| vampire bat | b | 2 | 24 |
| 4-headed hydra | M | 2 | 24 |
| carrion crawler | c | 2 | 25 |
| killer red beetle | K | 1 | 25 |
| giant firefly | I | 4 | 26 |
| giant grey ant | a | 1 | 26 |
| wolf chieftain | C | 5 | 26 |
| abyss worm mass | w | 3 | 26 |
| displacer beast | f | 2 | 26 |
| giant fire tick | S | 1 | 26 |
| disenchanter bat | b | 4 | 26 |
| nexus hound | Z | 4 | 27 |
| vibration hound | Z | 4 | 27 |
| killer fire beetle | K | 1 | 27 |
| basilisk | R | 3 | 28 |
| 5-headed hydra | M | 2 | 28 |
| bat of Gorgoroth | b | 3 | 28 |
| Beorn, the Mountain Bear | q | 0 | 28 |
| catoblepas | q | 2 | 29 |
| purple worm | w | 3 | 29 |
| giant black scorpion | S | 3 | 29 |
| giant army ant | a | 3 | 30 |
| giant blue ant | a | 2 | 30 |
| killer slicer beetle | K | 2 | 30 |
| death watch beetle | K | 3 | 31 |
| doombat | b | 2 | 32 |
| serpent of the brownlands | J | 2 | 32 |
| mûmak | q | 2 | 35 |
| wereworm | w | 3 | 35 |
| impact hound | Z | 4 | 35 |
| gravity hound | Z | 4 | 35 |
| inertia hound | Z | 4 | 35 |
| giant fire ant | a | 1 | 35 |
| killer iridescent beetle | K | 2 | 37 |
| abyss spider | S | 3 | 38 |
| 6-headed hydra | M | 2 | 39 |
| giant roc | B | 3 | 40 |
| 7-headed hydra | M | 2 | 40 |
| disenchanter worm mass | w | 3 | 40 |
| hellhound | C | 2 | 42 |
| The Queen Ant | a | 2 | 42 |
| multi-hued hound | Z | 6 | 43 |
| 8-headed hydra | M | 2 | 44 |
| greater basilisk | R | 2 | 45 |
| killer white beetle | K | 2 | 45 |
| winged horror | B | 3 | 48 |
| ancient spider | S | 5 | 48 |
| time hound | Z | 4 | 51 |
| nether hound | Z | 4 | 51 |
| plasma hound | Z | 4 | 51 |
| The Phoenix | B | 3 | 54 |
| dracolisk | D | 2 | 55 |
| Shelob, Spider of Darkness | S | 3 | 55 |
| 9-headed hydra | M | 2 | 57 |
| werewolf of Sauron | C | 2 | 63 |
| spider of Gorgoroth | S | 3 | 63 |
| chaos hound | Z | 4 | 64 |
| Tevildo, Prince of Cats | f | 3 | 66 |
| jabberwock | H | 3 | 68 |
| nightcrawler | J | 3 | 69 |
| hound of Tindalos | Z | 5 | 69 |
| aether hound | Z | 5 | 74 |
| Ungoliant, the Unlight | S | 1 | 75 |
| serpent of chaos | J | 3 | 78 |
| Draugluin, Sire of All Werewolves | C | 2 | 83 |
| The Tarrasque | R | 2 | 86 |
| Huan, Wolfhound of the Valar | C | 1 | 90 |
| Carcharoth, the Jaws of Thirst | C | 1 | 90 |
| Wolf-Sauron | C | 0 | 99 |
| Serpent-Sauron | J | 0 | 99 |
+-----------------------------------+-------+--------+-------+
178 rows in set (0.002 sec)