It was purportedly big and heavy.
I'd say a little of both.
The Transformers cartoon
The Alligatorcon was created by the Constructicons from the remains of the disassembled Optimus Prime after he was captured by the Decepticons. The creature was let loose into the sewers beneath New York City which was being redecorated into New Cybertron. Scrapper noted that they made good use of Prime's remains.
In the sewers, the drone encountered the Autobots Ratchet, Hound, Mirage and Bumblebee, who believed it to be a simple mindless beast. They tricked it into an abandoned train where it got trapped and sent down the tracks. It was only later that they realized that Optimus Prime had been disassembled after encountering his head in the Decepticon base. Hound finally realized why his scanner kept picking up Prime when the Alligatorcon attacked.
They sought the creature again in the sewers where they struggled to capture it until Prime used his remote controls to bring the beast in line. After which, Ratchet used the parts to reassemble Optimus Prime at the expense of the poor Reptilicon Alligatorcon. Talk about animal cruelty.