Leopard geckos are a species of gecko that are able to re-generate a new tail if it happens to drop its current one. When the tail grows back, it will be a little disfigured. Sometimes it may be wider in some areas, or it could be stubby. After a leopard gecko looses its "original" tail, the new one will never look the same way the original one had.
Various reasons.
stalking prey
scent marking
showing aggression
If it is Spring at that time, the one who shakes its tail is a Male and is looking for a mate.
if they only shake their tail a bit it means there about to pounce
fat tail leopard geckos tail are much larger than normal leopard gecko tails.The markings are different leopard geckos have a different personality
If a leopard gecko is threatened, it will drop it's tail. the tail creates a diversion and wiggles on the ground while the leopard gecko runs for safety.
African fat tail gecko
When a leopard gecko feels threatened it loses its tail. The tail still moves because it has nerve endings in it, and will distract the enemy while the leopard gecko gets away. Eventually the leopard gecko will grow a new tail but it will not be as pretty as its old tail. It will grow back in a "light bulb" shape instead of sleek and straight.
lose its tail
A Leopard Gecko stores its fat in its tail.
Yes, a leopard gecko drops its tail when threaten. It does this to distract the attacker so that it would attack the tail which is no longer on the gecko but still moves and wriggles. (Like some kind of cat toy.)
It will die if it does
The above leopard gecko morph is a Tangerine, "Carrot Tail" & "Carrot Head"
Female leopard geckos should weigh at least 45 grams before being bred.
The Leopard gecko is not related the the fat tail gecko and live in different regions across the globe. The Leopard gecko requires much dryer and arid areas with temps reaching 100+F. The fat tailed gecko needs more humidity and not so much heat with temps ranging from 78-90F.