You never know where you'll spot TV's coolest guest star lineup.

But maybe your 3-year-old does.

This week of new episodes on Disney Junior's Special Agent Oso (weekdays at 1 p.m. ET/PT) features Mel Brooks, Freddy Rodriguez, Doris Roberts, Sarah Chalke and other great performers.

Okay, it's just their voices, but still.

The Emmy-nominated series stars Sean Astin (The Lord of the Rings) as the voice of Oso, a bumbling stuffed panda who asks home viewers to help him help kids with everyday tasks.

Disney Channel quotes Brooks saying, "I did Special Agent Oso because my 5-year-old grandson Henry watches the show, and I wanted to surprise him with an appearance."

A better reason than most for grabbing that next showbiz gig.

Here's the big week on Special Agent Oso:

MONDAY, APRIL 4

"Snapfinger/On Old MacDonald's Special Song" - Oso helps teach Spencer and Nicole how to snap their fingers to their favorite tune. In the second story, Oso steps in to help Henry learn how to play "Old MacDonald" on the piano while Grandpa Mel (Mel Brooks) naps nearby.

TUESDAY, APRIL 5

"License to Order/Table Manners are Forever" - Oso helps Anastasija order her own healthy meal at a restaurant. Freddy Rodriguez (Ugly Betty) voices the role of Anastasija's health-conscious father. In the second story, Oso teaches Zack table manners in preparation for a fancy dinner.

WEDNESDAY, APRIL 6

"Lost and Get Found/A View to the Truth" - When Juan gets separated from his mother in a department store, Oso helps him stay calm and teaches him what to do when he gets lost. Rebecca Romijn (X-Men) guest stars as Miss Garcia, a store clerk who helps Oso reunite Juan with his mom. In the second story, Oso helps Lena learn how to tell her Grandma (Doris Roberts of Everybody Loves Raymond) the truth about a broken vase.

THURSDAY, APRIL 7

"A View to a Fire Drill/Thunderbelt" - Oso leads Marie and her friends through a practice fire drill. In the second story, Oso teaches Maya how to buckle her seat belt before she and her safety-conscious mom (Jenna Elfman of Dharma and Greg) head to a picnic.

FRIDAY, APRIL 8

"Quantum of Celery/Drink Another Day" - Oso assists Audrey with making a healthy snack that she can bring to school and helps Athena learn how to drink from the water fountain at the playground when preschool director Miss Kalfas (Sarah Chalke of Mad Love) encourages her students to stay hydrated while playing outside.