Swathed in the shadow of the towering beast, the creature was a pathetic sight. The narrow eyes painted a picture of languid awe, a fear overcome by idle curiosity. Standing in the crater-like footprint impressed upon the dirt road, it looked no more than a stubborn weed refusing to yield. Sinewy arms hung limp and twisted from a frail body of rough wizened skin, like bark ready to be broken.
Ironically, it was the snapping of a twig that had caught the Hulk's attention. He'd wheeled around expecting an attack, only to find a harmless sprig. His fists were still clenched.. Hulk had learned to be suspicious from years of persecution. Was the plant a decoy or was it more than met the eye? Questions and observations from Banner's mind floated at the edge of his subconscious, but Hulk felt only anger. All he wanted was to be left alone.
An intimidating growl rumbled from the Hulk's throat as he leaned forward and sniffed loudly. A leaf on the creature's head stirred like a flag in the breeze, but the plant-thing seemed unperturbed.
"I am Groot."
Hulk frowned. Experience had deprived him of the luxury of trust. Nobody deserved the benefit of the doubt. Not even a stick. Bellowing to the skies, he beat his enormous fists against his chest and stamped the ground. The ground shook and dust kicked into the air as another
Once again, Groot was impassive. The shrub-thing didn't move a fraction. It stared dreamily, unblinking, into the Hulk's fury-filled eyes. With the sound of a creaking floorboard, Groot's mouth worked open and he spoke again from the broken hollow.
"I am Groot."
The statement was no louder than before. There was no change in intonation or urgency, no sign of fear or aggression. Only the statement, as it was before.
Again Banner's mind reached out to offer platitudes, but Hulk ignored it. The plant-life's utterances were grating. Whatever it wanted, Hulk desired no part in it. For a time, Hulk glowered, his teeth bared and muscles tensed, but Groot still refused to move or explain his presence. At last Hulk reached out a massive hand and grabbed the twig-creature and pulled it from the ground. Barely a foot from the ground, the Hulk's efforts were undermined.
Woody tendrils snaked into the floor and anchored Groot in place. Hulk heaved once then twice, but Groot refused to be budged. Now there was a trace of emotion in those wooden features. One the Hulk recognised with ease.
"Hulk is strongest there is!"
Slowly, the head of Groot began to rise in the air and Hulk allowed himself a triumphant smile. The next instant, he realized that something was wrong. While the top of Groot's form was higher, Hulk's hand had not risen at all and now felt pressure forcing his hand open.
Groot was growing in size.
As Hulk watched in disbelief, the spindly arms swelled and the frail body grew to the size of an ancient oak. Hulk released his grip and staggered back. Groot's eyes became dark menacing hollows, and he loomed over the Hulk, reversing their earlier roles.
"I am Groot."
This time the voice was low and rumbling, imbued with the might and nobility of the forest. It was as if nature itself had spoken. Hulk set his jaw, grim determination etched on his face. Once more, Bruce Banner tried to calm the Hulk, to discourage violence, but the din of rage drowned out all thought but one.
"Hulk smash!"
NB - I like to think this is an encounter that would end with, "Hulk like Groot." "I am Groot."