Perhaps in the same instance that the manticore decides to like Shrieky, Shrieky decides that he likes the manticore. It has after all, saved them from at least one of a pretty unpleasant bunch of cattish beasts, and it has a particularly nice way of making noises, and perhaps most importantly, it hasn't decided to try and kill either of them.

So he responds to the little headbutt into his leg, with another happy, musical imitation of manticore speak, before reaching down to give it a fond (and extremely careful) little pat on the head.

"Are you all alone here?" He adds, in English now, "Poor Manticore."

The manticore may not understand, but in the worst case scenario, they can just go back to making noises at each other. He glances up to Wolfgang, still lavishing little pats on the purring beast, "What should we do? Could he come with us, do you think?"