He may be best known for his improv work with the Windy City Women Improv Troupe, but he has also acted in many TV shows and films, provided voice acting for TV animations and video games, and worked as a dialect coach.
Alcantar toured and performed with The Second City in both Toronto and London, Ontario. From 1989 to 1998, Alcantar taught at the Players Workshop of The Second City, directing 16 shows there. He has a BA in Theater and MFA in Acting from the Theatre Conservatory at Roosevelt University in Chicago, where he taught as well.
After relocating to Vancouver, British Columbia in 1999, Alcantar landed guest star or recurring roles on numerous shows, including Stargate SG-1, Dead Like Me, Da Vinci's Inquest, The Dead Zone, The Collector, Andromeda, Dark Angel, Millennium, Strange World, Honey I Shrunk the Kids, Just Deal, Cold Squad, Los Luchadores, The Outer Limits, and Breaking News. He had a recurring role on NBC's series American Dreams.
Alcantar performed in the award-winning mockumentary Best in Show, the all-improvised film directed by Christopher Guest. He also appeared in MVPII, The Rhino Brothers, Ballistic: Ecks vs. Sever, The Charlie's Angels Story, Chestnut: Hero of Central Park, Hope Springs, Fantastic Four, His and Her Christmas and In the Land of Women.
Alcantar has had lead and principal roles in the animated shows Slammin' Sammy, Being Ian, Evolution, Inspector Gadget and the Gadgetinis, Kong, Gundam Wing, Journey to the Center of the Earth, and Megaman Net Warrior. He has provided both voice and body to the upcoming Electronic Arts' video game The Godfather: The Game, as well as doing multiple voices for multi-award winning SSX On Tour. Alcantar has also been the dialect coach on the features Slither, Whisper, and The Wicker Man with Nicolas Cage.