human dynamo vs ball of fire

human dynamo and ball of fire both are nouns.

Word	Noun	Adjective	Verb	Adverb
human dynamo	Yes	No	No	No
ball of fire	Yes	No	No	No

As nouns, human dynamo and ball of fire are synonyms defined as:

human dynamo and ball of fire: a highly energetic and indefatigable person

Other synonyms of human dynamo include fireball, powerhouse.

human dynamo (noun)	ball of fire (noun)
a highly energetic and indefatigable person	someone whose career progresses rapidly
	a highly energetic and indefatigable person