Any animal that is considered to have cold blood, or whose ability to regulate body temperature depends on outside factors like sunshine or a warm rock surface is considered an ectotherm.
Fishes, amphibians, reptiles, and invertebrates are all ectotherms.
Animals that can keep a consistent body temperature no matter the outside temperature are said to be endothermic.
All of the birds and mammals are endothermic. Even some fishes are thought to have endothermic properties.
Frogs are ectothermic amphibians that cannot adjust their internal temperatures, unlike birds and mammals.
Instead, they must use external heat sources to warm up, a process known as thermoregulation.
Ectotherms regulate their body temperature through behavioural mechanisms.