It seems to mean that Jack's presence was drawing out the evil in Roger.
A sentence like "The woman crept up to the safe silently, slipping from shadow to shadow." would indicate sneakiness.
The past participle of "crept" is "crept." It remains the same in both the past tense and past participle forms.
The future tense of crept is will creep.
Crept is a verb. It is past tense of creep.
infinitive: creep past: crept past participle: crept
Crept is the past tense and the past participle of the verb to creep.
The past tense of "creep" is "crept".
Crept is already the past tense of creep.
The lion crept up on the unsuspecting prey.
the crept in the house is very harmful.
The burgular slowly crept up the stairs.