Liam O’Brien is an accomplished actor, writer, director, and producer in the world of animation and games. He’s lent his voice to the worlds of Star Wars, Transformers, the Marvel universe, and beyond. He is also a founding member of “Critical Role”, the long running, live-streamed RPG game on Twitch. He plays with fellow actors Matthew Mercer, Taliesin Jaffe, Travis Willingham, Laura Bailey, Sam Riegel, and Marisha Ray. On Critical Role, he is known for playing the characters Vax’ildan Vessar, Caleb Widogast, and Orym of the Air Ashari.

Liam is appearing Saturday and Sunday of MomoCon 2026. Critical Role guests will have only pre-reserve autograph sessions available, more details about reservations coming soon! The Critical Role panel will not have a reservation needed.

Special Note – Critical Role Autographs and Photos – Jan 5th 1p ET

Critical Role autograph and photo presales begin Monday, January 5 at 1p ET. If you’re planning to get an autograph or photo with the Critical Role cast, we recommend purchasing early.  On site autograph and photo purchases will not be available, however the Critical Role panel will take place on Saturday of con and have no extra fee or reservation.

Presales go live at 1:00 PM ET on Monday, January 5 and the link will be available on on the autographs and guest pages a few hours before the date/time!

Photo Op (single) – $75.25
Photo Op (whole group) – $462.25

8×10 Photo Autograph – $64.50
Premium Autograph (funkos, statues, trading cards) – $86.00
Autograph/Selfie combo – $86.00
Standard Autograph – $53.75
Table selfie – $53.75
Video or Voice Recording – $107.50