elastic
spirited
able to adapt
adaptable
adaptive
adjustable
airy
alterable
alterative
bendable
bouncing
bouncy
bounding
breezy
buoyant
carefree
changeable
checkered
convalescent
corky
debonair
effervescent
ever-changing
expansive
extensile
flexible
flexile
fluid
free and easy
impermanent
jaunty
kaleidoscopic
light
lighthearted
lightsome
lively
malleable
many-sided
metamorphic
mobile
modifiable
movable
mutable
nonuniform
perky
permutable
plastic
protean
agile
compassionate
durable
extensible
knowledgeable
long-lived
optimistic
pliable
resistant
robust
rubbery
self-reliant
self-sufficient
soft
springy
supple
tough
versatile
well-trained
brilliant
brittle
fragile