I saw pack roughly 15 direwolves, and they were attacking a max level mammoth. After a few seconds, there wasn’t a single trace of that mammoth’s existence. Do not mess with them, especially when they are in numbers.
I watched a pack of these killers destroy a rex but some of them died in the process but I tried to take them on myself and nearly died. NEVER and I mean NEVER underestimate the power of these killer dogs.