The appearance of the Australian marsupial prompted race officials to deploy the red flags, forcing riders back into the pit lane while the track was checked. The interruption added an unusual twist to a session that had already been disrupted by a collision involving Marco Bezzecchi and Alex Márquez.
Fortunately, the wallaby escaped without an apparent incident, and practice resumed after the track was declared safe.
Wallaby causes second red flag
The animal appeared on the circuit shortly after the session restarted following Bezzecchi's collision with Márquez.
The first red flag had been shown after Bezzecchi made contact with the rear of Márquez's Gresini Ducati, sending debris across the track and forcing officials to stop the session for a clean-up.
The second interruption came when the wallaby crossed the circuit, prompting another stoppage as riders and officials prioritised safety.
Phillip Island is known for its wildlife, but an animal entering an active MotoGP session presents a serious risk to riders travelling at high speed.
The incident ended without any reported collision between a rider and the animal.
Bezzecchi leads the way despite dramatic session
Despite his earlier collision with Márquez, Bezzecchi recovered to set the fastest time in the afternoon practice session.
The Aprilia rider recorded a lap of 1 minute 26.775 seconds to finish ahead of Trackhouse Aprilia's Raúl Fernández, who was 0.072 seconds behind.
Marc Márquez secured third place, a further 0.054 seconds off the pace, as Aprilia continued to demonstrate strong speed ahead of the weekend's racing.
The top 10 also included Ai Ogura, Jorge Martín, Álex Márquez, Enea Bastianini, Pedro Acosta, Diogo Moreira and Fabio Di Giannantonio. Those riders secured direct passage to the second qualifying session.
Álex Márquez later crashed during the closing stages, but his earlier lap was sufficient to keep him inside the top 10.
Jack Miller faces qualifying challenge
Australian home favourite Jack Miller endured a difficult day, suffering crashes during both Friday sessions.
The Pramac rider finished 12th in the afternoon practice, narrowly missing automatic qualification for Q2. He will therefore have to compete in Q1 to secure a place in the second qualifying session.
Miller's performance will be particularly important to local supporters, as Phillip Island is hosting its final Australian MotoGP round before the event moves to Adelaide in 2027.
Phillip Island prepares for qualifying and sprint
Attention now turns to Saturday's qualifying sessions and sprint race, with riders expecting further challenges from the circuit and potentially changing weather conditions.
Bezzecchi will take confidence from his fastest time, while Márquez and championship contenders will aim to improve their positions before the sprint.
For the wallaby, however, the brief appearance may have been the most unexpected moment of the day at a circuit where wildlife remains part of the Australian Grand Prix experience.