| ECTOTHERMIC | Of all animals other than birds and mammals, having a body temperature regulated by external sources (11) |
| COLDBLOODEDNESS | Quality of having a body temperature that varies with the environment (4-11) |
| RODENT | Mammals having a single pair of constantly growing incisor teeth |
| MUTATE | Change a temperature regulated externally by mum (6) |
| BEAST | Any animal other than man (5) |
| LARGEST | Like the blue whale out of all animals |
| NUTATION | In astronomy, a periodic oscillation of the earth's rotational axis caused by external gravitational forces (8) |
| STOWAWAYS | Those looking for a free ride to WA restricted by external influences (9) |
| ECONOMIC | Cost-effective small company with external source of income (8) |
| ASEITY | I agree to hold links back, having no external source |
| DETERMINISTIC | Controlled by external causes and not free will |
| TINNITUS | The perception of sound that does not have an external source, e.g. ringing in the ears (8) |
| FAUNA | Derived from the name of the sister of a Roman god of forests, a word for the assemblage of all animal life in a particular region or time (5) |
| AMNION | Inner of the two membranes enveloping the embryos of reptiles, birds and mammals, enclosed by the chorion (6) |
| VAMPIRE | Bat of Central and South America which feeds on the blood of birds and mammals (7) |
| ECTOTHERM | Cold-blooded animal whose body temperature is maintained by absorbing heat from its environment; i.e. any animal except birds and mammals (9) |
| AMNIOTE | Team on tour, taking interest in a group of reptiles, birds and mammals (7) |
| LEPORID | Relating to lagomorph mammals having long ears and limbs and a short tail, such as rabbits and hares (7) |
| SKUNK | American musteline mammal having a black and white coat and bushy tail (5) |
| VEGANISM | The practice of abstaining from the consumption and use of all animal products (8) |