Puu-chan, known as Putera in Japanese media, is a small robotic companion modeled after a Pterosaur. It features an orange-red exterior and a white underbelly. After the main protagonist joins the Time Police, Puu-chan serves as his guide and partner.

Assigned specifically to the prehistoric protagonist, Puu-chan patrols different historical periods with him. Its primary functions include providing contextual information about historical events and figures during time travel, correcting misinformation among the team, and relaying details about Time Shifters. The character interfaces with the Ridon device to contact the team's scientific advisor and summon Time Shifter assistance. A critical ability is the Memory Beam Erase Mode, which removes memories of 25th-century visitors from individuals in other time periods to prevent temporal contamination. Surveillance is another function, with its eyes acting as cameras to monitor and report mission progress.

Personality-wise, Puu-chan exhibits informative and cautious traits, often withholding knowledge to avoid timeline disruptions. Despite its robotic nature, it displays emotional responses like fear and discomfort, notably protesting rough treatment by a historical figure. The character frequently becomes a target for capture by antagonists due to lacking defensive capabilities.

Linguistically, the Japanese name "Putera" derives from "Pterosaur," with the "-ra" suffix suggesting a feminine connotation. The affectionate diminutive "Puu-chan" implies a youthful characterization relative to other cast members. For English adaptations, the character was renamed "Pterry" and altered to be male. Merchandise occasionally depicted color variations, such as a more yellow appearance due to ink reactions, though the core design remained consistent in official media. Information is limited to the core series and manga.