[The way Venkman's managing to hold an actual back-and-forth conversation with Roach immediately reminds Winston of how Ray and Janine have somehow become capable of deciphering Slimer's speech. ...but that's a comparison he doubts Peter would appreciate- so he's keeping it to himself.]

[Meanwhile, he goes to reach a hand back into his pocket, pulling the Pokeball out again. If Venkman can get this used to hanging around a bug bigger than himself, then hopefully Winston can at least test the waters with introducing him to his own starter.]

...well, while we're already getting acquainted-

[When he presses the button on the ball, the ray takes the shape of a mudbray. It on its feet between the two ghostbusters- announcing its presence with a loud, ungraceful honking noise.]

This is my mudbray, her name's Brooklyn. ...Brooklyn Supreme. Brookie, say hi to Peter.

[Brookie takes one look at Venkman. She snorts with her teeth bared in some sort of mocking grin, before turning her attention towards her owner, bowing her head down to his feet so she can attempt to untie his shoelaces with her teeth. ...Winston just sort of passively looks down at her with a tired smile as this is unfolding.]

Aw... look at that, Pete- she wants to learn how to untie knots.